One of the most easily recognized congenital orbital lesions is the group of choristomas commonly referred to as dermoid cysts . Correct pathological terminology would further delineate these lesions as epidermoid cysts (only showing histologic evidence of epidermal components), dermoid cysts (adnexal structures as well as epidermal components), and lipodermoid cysts (where fat is a prominent feature of the choristoma). All of these lesions are choristomas, which is derived from the Greek word choristos. This means separated and the term is applied for normal tissue in an abnormal place. For ease in terminology, the more popular term dermoid cyst will be used in this chapter to refer to this entire group and will not specifically define the histopathological contents. Lipodermoid cysts have a typically subconjunctival location and are rare as a subcutaneous entity but have been included in this section due to their similar genesis.

Dermoid cysts account for 1–46% of all pediatric orbital lesions in the series revealed in Table 35.1, with most oculoplastic and orbital textbooks indicating that 40–50% of all orbital pediatric lesions are dermoids. These cystic tumors arise from epidermal rest cells pinched during embryogenesis by the underlying bony structures as they advance toward closure. Periorbital dermoids account for approximately 10% of head and neck dermoid cysts. Most occur near the frontozygomatic or frontonasal suture.

Dermoid cysts can be divided into superficial and deep varieties [1]. Superficial dermoids have a classic appearance as painless, firm, sometimes mobile subcutaneous masses usually lateral in the upper eyelid and anterior orbit (Fig. 35.1). Parents usually discover these lesions in the first year of their child’s life as the child grows and loses periorbital facial fat, revealing their location, or by accidental palpation, usually during washing of the child’s face. Rarely, superficial dermoids can present as an acute inflammatory lesion with periocular erythema, tenderness, and swelling due to rupture of the cyst with resultant subcutaneous inflammation from the extruding keratin. This presentation usually arises from direct trauma with resultant cyst rupture. Other sites of occurrence are medial in the upper lid near the frontonasal or frontolacrimal suture or in the temporalis fossa (Figs. 35.2 and 35.3). Most are 1–2 cm in size and grow in tandem with the child’s maturation.

Deep orbital dermoids remain hidden for longer periods, presenting later in life with the slow onset of proptosis or globe dystopia. If significant combined orbit/temporalis fossa components are present (the so-called dumbbell-type dermoid) or if they are isolated to the temporalis fossa, swelling of the temple area can be the initial presentation [2]. Most deep dermoids are located laterally in the orbit near the sphenozygomatic suture and can involve the lateral rectus muscle, about the superior orbital fissure, or extend through this into the intracranial cavity (Fig. 35.4). Deep orbital dermoids are less common in the posterior medial orbit where they arise adjacent to the sphenoethmoidal suture. An additional presentation is that of a draining fistula from the lateral upper eyelid or the temple [3]. For deep orbital dermoids, physical examination usually reveals a smooth, rounded mass just palpable inside the anterior orbital rim or, more typically, no specific findings other than proptosis, globe dystopia, or, in the most advanced cases, optic neuropathy.

Imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI) are needed if the dermoid is fixed and nonmobile or presents with inflammatory signs or fistulization, or if proptosis, globe dystopia, temporalis fossa swelling, or optic neuropathy are present. Generally, imaging studies should be ordered for any lesion suspected of being a dermoid that is not in the superolateral quadrant of the orbit. This is due to the fact that orbital dermoids can dumbbell into adjacent structures. Fig. 35.5 depicts a temporal dermoid that extends into the orbit. Fig. 35.6 is of a dermoid that fistulized to the skin and was noted to extend into the skull base. Fig. 35.7 is of a medial dermoid that is an extension of a nasal dermoid. The goal for imaging studies is to confirm the clinical diagnosis and determine, in suspicious clinical cases, the presence or extent of a deep orbital component. Depending on the intraluminal tissue components of the cyst, imaging findings can be quite varied. Generally, well-circumscribed, superficial dermoids show a uniform appearance on CT evaluation representative of the intraluminal keratin, but they may also show radiolucent areas if fat is present (Fig. 35.8). It is rare to see calcium in these cysts, although giant orbital dermoids may show a rather characteristic finding of calcium in the cyst wall, which is rarely seen in orbital lesions other than an occasional mucocele [4]. MRI usually shows a uniform signal with phase-shift artifacts along the cyst borders but can show a dramatic multisignal appearance if fat is present due to its high signal intensity on T ₁-weighted images (Fig. 35.4). Bony defects are rare in children except for occasional minor indentation molding; adults with deep dermoids can have impressive bony molding or erosion (Fig. 35.9). A full-thickness bony defect may occur with dumbbell dermoids as the intraorbital and temporalis fossa portions connect through the lateral orbital wall, and widening of orbital fissures may occur for those deep dermoids that extend intracranially (Fig. 35.6). Large intraorbital dermoids can be initially misdiagnosed as malignant lesions. This is especially true is dermoids with packed keratin, which can show diffusion restriction on diffusion-weighted imaging (DWI) on MRI. Fig. 35.10 is an example of such a lesion.

The treatment for orbital dermoids is surgical excision. The timing of the excision is based on the size of the lesion, the presence of lid or globe displacement, any inflammation, and, at times, parental wishes. Since these lesions grow with the child, most become increasingly obvious and may displace normal lid or orbital structures, including the globe itself. Removal should be performed so that accidental rupture does not occur from periocular trauma, which can spread the cyst contents subcutaneously and make complete extraction difficult. Dermoids left to enlarge for years can cause permanent bony or soft tissue malformation. In addition, delaying dermoid cyst excision can lead to skin fistulization (Fig. 35.6). Superficial dermoids of the lateral and medial orbit can easily be reached by a lid crease incision, which allows excellent visibility of the lesion with placement of the cutaneous scar in the natural medial or lateral upper lid crease [5, 6]. This has virtually replaced direct incision over the lesion for superficial dermoids.

Care must be taken to remove the dermoid intact without rupturing the capsule to avoid postoperative orbital granulomatous inflammation, which can smolder with retained dermoid components. The use of a cryoprobe can be of value in dermoid excision particularly if a small break occurs in the capsule (Fig. 35.11). The cryoprobe can be applied over the rent, sealing it and allowing for continued traction on the dermoid to complete the dissection. Also, the surgeon must look for small extensions connected to bone when the dermoid is relatively immobile on clinical evaluation, as this may represent vestigial portions of the original epidermis pinched between bony structures and could lead to a subsequent inflammatory reaction or recurrence of the lesion if a portion of the dermoid remains unresected.

The surgical excision of deep orbital dermoids is typically undertaken in teenage years or in adulthood, since this is when most of these hidden orbital lesions are discovered. The decision to remove the dermoid depends on its size, its location, its relationship to surrounding structures, and how it affects the function of these structures. These same factors also help determine the approach used for removal of the dermoid; otolaryngologic or neurosurgical consultation and surgical support may be necessary for ethmoidal or deep orbital apex/orbital fissure involvement.

Dissection of the orbital portion is done first, attempting to completely shell out the lining of the dermoid as free of normal orbital tissues as possible. Within the confines of the orbital space, visualization of the base is attempted. If the lesion cannot be directly mobilized for removal of its base from its bony attachments, evacuation of the dermoid’s contents allows room for mobilization and excision of the remaining portion. Care must be taken to avoid spillage of the dermoid contents into normal orbital tissues. For deep dermoids that extend into adjacent cavities, surgical removal may be approached through that cavity. This approach may also be used with dumbbell dermoids that occupy the orbit and temporalis fossa. Direct removal of the temporalis portion through a lateral orbitotomy incision can be assisted by removal of the lateral orbital rim and wall, allowing access to the orbital portion (Fig. 35.3). For superficial dermoids , complete removal of the cyst wall is necessary to prevent recurrence or orbital inflammation. Some lesions, especially those that extend intracranially through the orbital apex, may be impossible to remove due to potentially severe functional deficits, but, if evacuated and conservatively resected, may take years to reform. Some surgeons have advocated marsupialization of the dermoid but this could be technically challenging for deeply placed lesions and could offer a route for infection from an exogenous route.

Sclerotherapy with the aid of fluoroscopic needle guidance is an option for deep orbital lesions. Some cystic lesions are amenable to this treatment [7]. The major risk of dermoid cyst removal is recurrence. Intraorbital rupture, incomplete cyst removal or delayed removal may allow for islands of cyst epithelium to continue to produce keratin. This can cause chronic inflammation and cyst recurrence that can take decades to present (Fig. 35.12).

On histopathological examination, the lining of the cyst consists of typical keratinizing stratified squamous epithelium with variable adnexal structures. Cyst contents usually consist of keratin alone, but fat, hair, and sebaceous material may also be seen. An interesting finding noted by several authors involves the identification of small ruptures in the cyst wall with a surrounding limited granulomatous inflammatory reaction in a number of cases. None of these cases had coincident signs of orbital inflammation, indicating that a large rupture is probably necessary to produce clinically evident signs of inflammation. It is clear, then, that the dreaded complication of persistent orbital inflammation from incomplete cyst removal probably requires large amounts of residual debris and that small evacuated remnants are well tolerated, although they are highly likely to recur even decades after resection. Complete cyst removal, therefore, remains the goal in the surgical management of this lesion.

Dermolipomas represent an ectopia of skin and its adnexal structures within conjunctival tissues. Usually located temporally on the globe, argument exists as to whether dermolipomas represent a true orbital condition or, rather, a conjunctival choristoma. In any event, one cannot argue about the potential involvement of orbital structures, including the lacrimal gland, lacrimal ductules, or the lateral rectus muscle, by these congenital growths, making discussion of these unusual lesions important for the pediatric oculoplastic surgeon. Inspection under a slit lamp is critical. If hairs are visible the lesion is more likely a dermoid cyst. The lack of hair supports the diagnosis of dermolipoma.

Table 35.1 indicates the rarity of dermolipomas with only 11 cases reported in all six series used to compile the table. This may represent the author’s preference for identifying these as conjunctival lesions or their individual propensity for avoiding surgical resection and, therefore, the relative absence of large numbers of these lesions in histopathologic studies. Most dermolipomas are discovered accidentally in late childhood or in the early teenage years, usually as the result of lid manipulation or, as in our experience, during the search for a presumed foreign body. Sometimes seen on an emergency basis at the request of the child’s primary care practitioner due to their sudden discovery, these yellowish-white, superotemporal epibulbar masses elicit alarmed reactions from the referring physician, patient, and parents who insist it is a new entity. Typically soft, moderately displaceable, and noninflamed, the surface is usually smooth but may have an irregular texture or hair-bearing areas (Fig. 35.13). Most are small and hidden completely by the lid, although some may be large enough to encroach upon the limbus. When bilobed, they may be more visible and thus more likely to be diagnosed at a younger age (Fig. 35.14). Their typical appearance and position should give the ophthalmologist every confidence in declaring their congenital origin. For lesions that have an anterior position, old photographs may show some of the lesion peeking out of the lateral canthal area, convincing parents and the patient of its long-time presence (Fig. 35.15).

Dermolipomas share the histopathologic features more typical of limbal dermoids than dermoid cysts [8]. The main differences between the histopathology of the dermolipoma and the orbital dermoid cyst are the presence of a stroma made of dense collagen bundles, a disproportionate amount of fat, and the usual absence of pilosebaceous units within the dermolipoma. Accordingly, dermolipomas are seen much more frequently in a number of congenital developmental disorders, usually involving the craniofacial complex: Goldenhar syndrome, Treacher Collins syndrome, linear nevus sebaceous syndrome, hemifacial microsomia, and in facial cleft 7 as described by Tessier [9]. Usually the other facial and cranial stigmata of these conditions will be obvious, but bilateral presentations of dermolipomas should prompt extreme suspicion for one of these conditions, if not already diagnosed.

Imaging studies are necessary only when surgical resection is anticipated, if globe restriction is found, or if the clinical appearance is not typical for a dermolipoma. CT evaluation demonstrates either a soft tissue-density mass or a cystic-appearing lesion with well-circumscribed borders and a radiolucent center usually identical to that of intraconal fat located temporally in the orbit (Fig. 35.16). Unusual posterior extension can help to explain motility restriction and caution the surgeon against deep orbital exploration due to involvement of the lateral rectus muscle (Fig. 35.17) [10]. Lacrimal gland dysfunction would be distinctly unusual, as would inflammatory signs.

Consideration of surgical resection should be tempered with the knowledge that more reports exist about the postoperative complications of dermolipoma resection than about the lesion itself [11]. The presence of large dermolipomas that cause lid vaulting from the surface of the globe and dellen formation, adnexal structures such as hair that cause persistent foreign body sensation, and the anterior protrusion of visible dermolipomas are valid indications for conservative resection of these lesions [12]. Complications generally result from attempts at complete resection. Intraoperatively, the boundaries of the lesion are difficult to define because the intraorbital fat may be separated by only an ill-defined fascial plane. The close proximity of the lacrimal ductules, the palpebral lobe of the lacrimal gland, the lateral rectus muscle, and the lateral horn of the levator palpebrae superioris further complicates complete resection. The surgical goal should be conservative resection of the symptomatic portion of the lipodermoid. In most cases this would involve resection of the visible epibulbar portion of the tumor up to but not into the fornix. This avoids the lacrimal ductules, the lateral rectus muscle, and the horn of the levator, while removing the most visible portion of the tumor along with any irritating adnexal structures. Complications such as blepharoptosis, diplopia, and keratitis sicca are more likely to be avoided. A frank discussion about these potential complications helps patients and their parents understand the potentially complicated surgical nature of dermolipoma resection and may make them more willing to accept a recommendation to forego surgical resection when only purely cosmetic indications exist.

Phakomatous choristoma (Zimmerman’s tumor) is a rare congenital tumor believed to represent ectopic ectodermal tissue of lenticular origin [13]. The clinical presentation is of a subcutaneous or preseptal orbital mass localized to the inferomedial aspect of the lower eyelid or orbit [14–17] (Fig. 35.18). The histological appearance is of ectopic lenticular epithelium that expresses lens-specific immunological markers for crystallin proteins and stains positive for immunohistochemical markers S-100 and vimentin, which are specific for filaments of lenticular tissue. A firm mass that may be adherent to the inferior orbital rim located in the inferior medial orbit (corresponding to the quadrant of the closure of the fetal fissure) [18–20].

Complex choristoma is the best term to describe a group of orbital lesions representing a variety of ectopic tissues found both superficially and deep within the orbit. Their presentation is often similar to a dermoid cyst. Located primarily in the lateral orbital compartment, they are most often discovered in late childhood due to the growth of the lesion announcing its presence. Some may be epibulbar in location, in which case a distinctly more vascular external appearance is seen, while others may occur deeper in the orbit [21, 22].

The most common ectopic tissue found in these orbital rests is lacrimal gland (Fig. 35.19), but brain, conjunctiva, and respiratory epithelium have also been reported [23–27]. These lesions are not extensions from contiguous structures but are isolated within the orbit, making their exact diagnosis difficult until surgically excised and pathologically evaluated. The existence of these tissues in the orbit results from erroneous migration of embryogenic tissues that settle with normal orbital tissues and later develop into their final histogenic form.

This cystic orbital lesion represents the arrested closure of the fetal fissure at approximately 4 weeks of fetal life (8-mm stage), resulting in a persistent ocular defect. Neuroectodermal tissue that is attached to and contiguous with the globe fills with aqueous fluid, resulting in slow expansion of the cyst and globe displacement that is usually superior and medial. The cystic portion can be variable in size on clinical presentation and the degree of microphthalmos may also be mild or severe [28]. Generally, the larger the cyst at birth the more microphthalmic the globe. If no globe is present, the term congenital cystic eye applies. This earlier embryogenic failure of development of the primary optic vesicle may mimic microphthalmos with cyst and can also present with a large, multicystic orbital mass [29].

Depending on the degree of failure in the fetal fissure, the cyst may be small or large at birth. A large colobomatous defect resulting from poor fetal fissure closure manifests with a congenitally large cystic component obvious at birth. These are typically unilateral, cause proptosis with superior globe displacement, and can have a characteristic bluish coloration. Transillumination can rapidly help one distinguish this condition from orbital teratomas and encephaloceles. Late cases of cyst enlargement have been reported even after decades of quiescence, indicating that some additional breakdown in cyst/eye coupling allows expansion in the colobomatous cyst [30]. Bilateral cases have been reported, but are often asymmetric and have been associated with 13q deletion syndrome, ring deletion of chromosome 18 and with trisomy 18 [31, 32].

Imaging techniques, including CT scan and orbital ultrasonography, can confirm clinically evident lesions or diagnose indeterminate ones. The cystic component is echolucent ultrasonically, while the microphthalmic eye shows some echogenicity due to the vitreous. CT or MRI can demonstrate the globe/cyst relationship along with the attachments to the cyst wall (Fig. 35.20). The cyst contents appear very close in density to normal vitreous on MR imaging [33].

The treatment of microphthalmos depends on the size of the cyst and the resultant functional orbital dysmorphism along with considerations involving the function and displacement of the globe (see also Chap. 39). Expanding large cysts with nonfunctioning microphthalmic globes are best addressed by complete cyst excision and enucleation. For huge cysts, drainage intraoperatively may be necessary to even begin dissection. Preservation of as much orbital tissue as possible is necessary with large cysts, because little may be left for coverage of an orbital implant. Dermis-fat grafts can work well in this situation, even in very young children, because these sockets may already be well expanded due to the large cyst size, allowing for placement of large amounts of autogenous material (see Chaps. 36 and 39). Smaller cysts with cosmetically acceptable globes can undergo successful removal of the cyst alone [34] (Fig. 35.21). Large cysts with orbital expansion and proptosis are best treated with excision (Fig. 35.22). Even repeated needle aspiration of the cyst has been successful in permanently reducing cyst size [35]. Despite these surgical avenues, observation will be all that is necessary for the majority of these colobomatous cysts along with cosmetic shell management in concert with an ocularist.

Paranasal sinus obstruction with resultant entrapment of mucus, pressure increase with eventual erosion of surrounding bone, and spread into adjoining head and neck cavities such as the orbit defines the term mucocele. If found to be infected, the term mucopyocele applies. Mucoceles have traditionally been thought to result from stenosis of the sinus ostia. A history of nasal or facial fractures, chronic allergies, recurrent or chronic sinusitis, chronic polyposis, or past sinus or nasal surgery reveals potential routes through which sinus ostium damage or scarring may occur. Others believe that mucoceles form when sinus mucosa cysts gradually enlarge, causing secondary obstruction of the sinus ostium [36]. A definitive cause based on historical information is lacking in about 30% of patients presenting with orbital involvement from paranasal sinus mucoceles.

Mucoceles presenting with orbital involvement in the pediatric population are rare. In the compiled series tabulated in Table 35.1, only 12 cases were identified among a total of 1820 pediatric patients with orbital processes, for an incidence of less than 1%. None of the series gives detailed information as to the cause of mucoceles in affected children. However, two particular conditions have been associated with mucocele formation in children: allergic rhinitis and cystic fibrosis [37, 38]. In adults, it is estimated that 60% of all mucoceles arise from the frontal sinus, 30% from the ethmoids, and the final 10% from the maxillary sinus. Sphenoid mucoceles are rare [39, 40]. In children, most mucoceles arise from the ethmoid sinuses secondary to the delayed aeration and formation of the frontal sinus that begins only around 11 years of age.

Clinical signs associated with orbital involvement of mucoceles include proptosis, inferior or lateral globe dystopia, upper eyelid swelling, telecanthus, diplopia secondary to gaze restriction, and decreased vision. Few patients have all these symptoms on presentation. The most common combination of symptoms is lid swelling and globe displacement. Palpation of a firm superonasal mass helps in the clinical diagnosis of mucoceles. Occasional episodes of more acute inflammation with pain, redness, and swelling, limitations of ocular motility, and displacement or proptosis of the globe may herald an infection or spontaneous leakage of the mucocele due to its continued expansion. Since the ethmoids are the most common location of pediatric mucoceles, lateral globe dystopia with associated hypertelorism and telecanthus is the most common presentation. Most cases are unilateral, but approximately 5% may involve both orbits.

Imaging studies easily delineate these lesions. CT scanning of the head and orbits remains the most valuable imaging modality due to its ability to localize focal areas of bony dehiscence, thereby providing delineation of the extent of the lesion as well as its morphology [41]. The identification of these bony dehiscences is important during the surgical correction of the mucocele to avoid penetrating into other cavities such as the intracranial space or orbit, resulting in potential recurrence, injury to the brain or eye, or spread of any infected material. The mucocele appears as a homogenous mass within the affected sinus that enlarges and expands the bony sinus margins rather than destroying them (Fig. 35.23b). Typically the contents are isodense with brain. With contrast enhancement, the cyst contents fail to enhance while the rim may enhance, especially if inflammatory episodes have occurred. Calcifications may be seen in the rim as well. The cyst may expand into the orbit or intracranial cavity if the bone erodes. The prolapsed cavity subsequently displaces intraorbital contents.

MR imaging may show these prolapses with more detail than CT [42]. Variations in the viscosity of the cyst contents along with breakdown and desiccation of solid components are the proposed explanations for the variable MR features, which are usually hypointense on T ₁-weighted images and hyperintense on T ₂-weighted images. Mucoceles have a fairly characteristic appearance, but congenital encephaloceles may present with similar clinical signs. CT should be able to show the bony avenue through which the sinus contents herniate into the cranium and orbit.

Mucoceles require surgical correction to avoid damage to nonsinus structures. Frontoethmoidal mucoceles have traditionally been treated by an external Lynch-type incision, yielding access to both the frontal and ethmoidal areas. This approach also lends itself to the identification and dissection of the periorbita from the epithelial lining of the cyst, isolating the orbital contents from potential injury when the cyst lining is peeled or obliterated [43]. In cases where previous inflammation or infection has occurred, the cyst lining may be adherent to and nondissectable from the periorbita. With most pediatric mucoceles involving the ethmoid sinuses, obliteration of the mucocele is less attractive due to continued facial growth in young children and the amount of surgery necessary to completely remove all ethmoidal cells involved. Reestablishment of drainage of the mucocele into the nasal cavity seems to be a worthwhile approach with ethmoidal involvement. A medial lid crease approach offers an external view through a cosmetically acceptable incision site (Fig. 35.23c–f). Alternatively, intranasal approaches with endoscopic guidance have enjoyed increasing utilization among otolaryngologists and may be applicable in these cases as well (Fig. 35.24 and see Chap. 9).

Occasionally, lacrimal drainage mucoceles are large enough to cause proptosis [44]. A large intranasal component can be seen such as the patient in Fig. 35.25, who was treated with an intranasal cyst removal. This can result in cyst reduction without the need for an orbitotomy or external DCR.

The potential surgical complications include recurrence, orbital injury, including diplopia from a misplaced or damaged trochlea, intracranial transgression with cerebral spinal fluid (CSF) leak through unrecognized bony dehiscences, and extensive bleeding from attempts to extirpate all cyst lining epithelium [45]. The most grave complication to the eye from endonasal endoscopic surgery was an inadvertent enucleation, which was has been previously reported [46]. Otolaryngologic colleagues can provide invaluable assistance in planning and completing the surgical repair of mucoceles in the pediatric population.

Teratoma is the term used to describe a neoplastic growth of tissue containing all three germ cell layers. Endothelial, epithelial, and mesothelial components can be found in these rare congenital tumors. These are believed to arise from primitive germ cells that may be ectopic or may have migrated during embryogenesis to the site of involvement. More common in sites other than the head and neck, only nine cases of orbital teratoma were recorded in the series tabulated in Table 35.1, for an incidence of less than 1%. Cervical, sacral, gonadal, and mediastinal locations account for over 70% of all teratoma presentations. Mamalis et al. reviewed the literature in 1985 and found approximately 60 cases primary to the orbit, including the two reported in their article [47]. Females outnumber males 2:1 with nearly all orbital teratomas present at birth.

Most orbital teratomas are small and appear similar to a well-circumscribed dermoid. Located adjacent to the globe instead of near the site of bony closures, some may be as large as 10 cm in diameter on presentation, creating a rather alarming appearance made even more grotesque if the face, sinuses, or cranium are also involved [48] (Fig. 35.26). Universally unilateral, most are located in the inferior orbit, displacing the globe superiorly and have a characteristic red-orange coloration when large and a yellowish-white appearance when small. The globe may be completely invisible, displaced under the upper eyelid, and so compressed that vision is lost. Rarely, they may extend into the intracranial space [49]. Smaller lesions that grow rapidly may show progressive signs of visual compromise such as decreasing motility, afferent pupillary defect, or an amaurotic pupil with continued globe displacement. Some cases with very small teratomas may show progressive proptosis with development of a palpable mass, mimicking other rapidly growing lesions of infancy, such as lymphangioma, capillary hemangioma, rhabdomyosarcoma, metastatic neuroblastoma, or leukemia.

Teratomas can be cystic or solid. CT evaluation demonstrates these internal features as well as the relationship to other vital orbital structures. Heterogeneity of the internal contents is frequent and calcifications are not uncommon in solid teratomas. The histopathology of teratomas shows evidence of all germ cell layer tissues in various stages of maturation. Intestinal structures, glandular elements, and secretory choroidal plexus are frequently found, accounting for cystic features within the teratoma and helping to explain its often rapid enlargement.

Treatment for these lesions is based on the size of the teratoma, presence of vision in the affected globe, and involvement of other orbital, sinus, or cranial structures. If vision is present, attempts can be made to separate the teratoma from the globe and optic nerve during orbitotomy. Successful preservation of vision is possible in some cases but is frequently not possible with large teratomas [50]. With no identifiable visual function and a deformed globe, limited exenteration of the globe and teratoma is undertaken in an attempt to preserve uninvolved orbital structures. Complete teratoma removal is important because of reports of malignant features in these tumors and the report of malignant transformation in an incompletely excised lesion [51, 52]. For those children too ill to undergo surgery, decompression of the cystic component may offer adequate temporization to allow for later successful surgery [53]. Complicated teratomas involving other cranial structures often require more radical surgical efforts, usually combining craniotomy and sinus surgery, by a team of appropriate specialists [54]. Incompletely excised teratomas require surveillance for regrowth and malignant transformation. Serum α-fetoprotein and human chorionic gonadotropin levels can be useful in monitoring tumor response when chemotherapy is used to treat recurrent, malignant, or unresectable teratomas [55]. Social service support for the family is necessary to help with planning for the child’s home care and to preserve parental/child bonding in these potentially devastating cases.

Cephaloceles represent the failure of embryonic surface ectoderm to separate from neuroectoderm, resulting in continued intimacy of these developing tissues. A persistent connection between brain tissue, meninges, or the combination of these with orbital contents is broadly termed orbital cephalocele. More specifically, meningeal herniation is termed meningocele, while the presence of both brain and meninges is called meningoencephalocele . The term encephalocele would apply to the herniation of brain alone, which in the orbit is usually heterotopic tissue without true connection to the intracranial cavity. It is hard to imagine a situation other than heterotopia where the brain would herniate without meninges. This herniation occurs through a bony defect in the frontal skull base that may extend not only into the orbit but also into the ethmoid sinuses, the nasal cavity, or the opposite orbit depending on the size of the defect.

Orbital cephaloceles are rare. Only six cases are reported in Table 35.1 for an incidence of approximately 0.3% among all pediatric orbital tumors. An exact occurrence rate is unknown, but an increased frequency is seen in Southeast Asia [56]. The highest association is seen among children with congenital craniofacial clefts where bony defects in a variety of skull areas lead to the herniation of intracranial contents [9] (Fig. 35.27). Anterior cephaloceles are usually visible from birth, while deeper lesions may not manifest until late childhood or early adulthood.

The location and size of the bony dehiscence and resultant tissue herniation through this dehiscence will determine the effect on the orbit and eye along with the clinical presentation. A sincipital cephalocele as depicted in Fig. 35.27 produces an inferior and lateral orbital dystopia. A more nasal herniation near the frontonasal suture will produce lateral globe dystopia, while a medial dehiscence more posteriorly near the frontoethmoidal suture will produce a clinical picture of later-onset proptosis and lateral globe dystopia. Far posterior dehiscences, such as is seen in neurofibromatosis with a missing greater wing of the sphenoid, may produce only proptosis. Centrally placed cephaloceles, termed basal cephaloceles, produce the classic features of a broad nasal root, hypertelorism, and telecanthus when large. These arise from dehiscences along the cribriform plate. These masses are usually soft and spongy and may enlarge with Valsalva maneuvers . Occasionally, a pulsatile quality may be visible. Some of these may not have a significant anterior component and may present later in life with ophthalmic signs resulting from encroachment of the cephalocele on the visual system. Morning glory disk, nasolacrimal obstruction, ocular motility abnormalities, monocular vision loss, and communication with the lower eyelid have been some of the findings resulting in the discovery of an associated cephalocele [57–60]. Rarely, a cephalocele may present as a mass below the medial canthus thus simulating a lacrimal mucocele or amniotocele. For this reason, orbital imaging should be considered, especially in the setting of an attempted probing and irrigation without successful lacrimal mucocele reduction. Fig. 35.28 depicts such a case of a medial canthal mass that was referred for a lacrimal mucocele ; however, a large cephalocele was noted on imaging.

CT proves to be the most useful imaging study. The extent and outline of the bony abnormality is easily seen, as is the connection of the cephalocele contents to the brain (Fig. 35.29). Demonstrating the tissue herniation is very important to the CT diagnosis of cephaloceles and helps differentiate these from lesions that may have a similar clinical appearance, such as superficial and deep dermoids, small teratomas, or mucoceles. This is important especially with small meningoceles because of the surgical implications of exploring these lesions and finding intracranial connections.

The treatment of orbital cephaloceles requires support from neurosurgical colleagues and may require the help of a craniofacial surgery team. The size, location, and extent of the cephalocele determine the approach to the excision and repair of both the bony and soft tissue involvement. Small, anterior lesions with minimal bony dehiscence can be approached extracranially with excision of the herniating material, enlargement of the bony defect to facilitate meningeal closure, bony repair with autogenous or banked bone, and cutaneous closure. Most cases, however, will require a careful preoperative plan that usually entails intracranial separation of normal brain and meninges from the herniating component, watertight repair of the dural defect, and elimination of the osseous opening with later excision of the orbital portion through extracranial routes (Fig. 35.28). Very large meningoencephaloceles require craniofacial support to tackle the formidable challenge of eliminating the defect itself but also repairing the secondary cranial and facial effects, resulting in a reduction of any exorbitism, telecanthus, or other associated abnormalities [61, 62]. Complete removal of the herniated portion is necessary to prevent recurrence.

Traditionally, the classification of orbital vascular lesions has been based on topographic description. While this schema is well ensconced in the medical literature and offers a semblance of immediate appreciation of the lesion when examining a patient, it offers little understanding of the embryologic origins, pathophysiologic determinants, and hemodynamic considerations that ultimately help categorize and effect appropriate management strategies. Several practitioners have championed the cause of reclassification of orbital vascular lesions in an effort to level terminology and definitions in this often confusing set of orbital lesions.

Rootman deserves credit as one of the first individuals to utilize strict pathologic and hemodynamic features to reclassify these vascular lesions into three categories: malformations, shunts, and new growths [63, 64]. New growths are not present at birth, have endothelial proliferation, and are usually well circumscribed radiologically. Infantile hemangioma, cavernous hemangioma, and single cell line neoplasms such as hemangiopericytoma and malignant angiosarcoma are examples of this category. Malformations are present at birth, grow parallel to the growth of the patient, have flat endothelial cells with dysplastic vessels, and are diffusely arranged in the orbit. Lymphangiomas (now called venolymphatic malformations) emphasize these clinical features. Shunts are an abnormal connection between the arterial and venous systems and can be congenital, acquired, or arise by malformation. Dural fistulas and arteriovenous malformations are representative of this class.

Stressing the importance of lesional hemodynamics as a classification tool, the Orbital Society has issued a consensus statement on the classification of orbital vascular lesions amplifying the importance of hemodynamics in the categorization of these processes [65]. Broken down into no flow, venous flow, and arterial flow malformations, no consideration is given to lesions that arise by new growth, leaving a large void for a universal classification scheme covering all orbital vascular lesions. The hemodynamics of the lesion do produce the majority of symptoms in the presentation and classification of the lesion, such as the rapid onset of proptosis, vascular congestion and swelling, orbital dysfunction and bruit associated with a high-flow carotid-cavernous sinus fistula versus the often low-flow dural fistula with its less obvious and often insidious onset of vascular dilation, increased intraocular pressure, mild proptosis, variable orbital dysfunction, and usual lack of an audible bruit. These hemodynamic features are what we recognize most in a clinical setting and utilize for diagnosis. As Rootman points out and as the Orbital Society classification demonstrates, the variability of vascular flow among lesions still creates difficulties in clinical diagnosis. One must consider not only hemodynamics and clinical presentation, but imaging studies to help determine the type of orbital lesion one is dealing with. While contrasted CT and MRI remain important first tools in accurate identification, one must consider more sophisticated imaging techniques such as Doppler ultrasonography, MR arteriography, and even invasive venography and arteriography when high-flow lesions are suspected. This may save the practitioners from emptying the “chocolate cyst” of a lymphangioma and discovering a congenital venous shunt that will challenge any practitioner’s orbital surgical skills in the face of potential exsanguination in a 3-year-old.

The International Society for the Study of Vascular Anomalies (ISSVA) updated its own classifications for vascular anomalies in 2015 [66]. Due to additional lesions identified since its previous scheme from 1997 (Table 35.2), Rootman has simplified this table to apply to orbital lesions and incorporated the previously published Orbital Society classification Scheme [67]. This is summarized below:

Vascular malformations often show a confusing spectrum of signs and symptoms at presentation and on pathological evaluation. This is not surprising given the multitude of vascular elements that can manifest in a single lesion (venous, arterial, lymphatic, and capillary elements). As such, one often cannot diagnose an orbital vascular lesion or determine the correct surgical or nonsurgical treatment based only on its clinical and radiologic features. One must be prepared to include the considerations of hemodynamic flow, neoplasia, and additional imaging studies to help choose correct treatment strategies. These newer classification attempts are meant to emphasize the diversity and variable combinations of features representing orbital vascular lesions. This section retains the established clinical classification system for these vascular lesions while awaiting future studies refining treatment strategies that correlate to the terminology utilized in the newer systems.

While most commonly affecting the cutaneous portions of the eyelids and face, infantile hemangiomas with orbital involvement are not unusual. The surface features identifying this condition to almost all practitioners can be missing with isolated orbital infiltration, making its diagnosis challenging. With this chapter devoted to benign pediatric orbital tumors, it is difficult to discuss isolated orbital infantile hemangiomas alone due to the spectrum of presentation and involvement one sees clinically; thus, cutaneous and deep lesions are discussed together in this section (see also Chaps. 6, 7, and 23).

The exact incidence of infantile hemangioma varies widely in reported series. Table 35.1 compiles 101 cases of pediatric infantile hemangioma in the six series surveyed. These cases include superficial hemangiomas (anterior to the orbital septum), deep hemangiomas (posterior to the orbital septum), and combined hemangiomas (both anterior and posterior components). This represents an incidence of 5.6% among all pediatric orbital lesions, which is less frequent than other benign processes, such as orbital cellulitis, dermoid cysts, idiopathic orbital inflammation, and thyroid orbitopathy for the series surveyed. Among these individual series, the incidence ranged from 0% to 11.8%, but in no instance was it the most common benign pediatric orbital lesion. Haik et al. reported on their experience treating 101 cases of capillary hemangioma in children and found that 33% of these patients had skin lesions alone, 7% had only orbital involvement without any cutaneous manifestations, and the remaining 60% had a combination of both superficial and deep components [75]. Females outnumbered males 3:2 and 95% of patients presented under 6 months of age. A distinct predilection for the superior orbit and lid is a consistent feature.

The clinical features of infantile hemangioma vary, depending on its subcutaneous depth. Superficial infantile hemangiomas start as small flat foci of dermal collections of abnormal capillaries characterized by endothelial cell proliferation into an organized network of basement-membrane-lined vascular channels that undergo rapid expansion over several weeks to months. Once well vascularized, their typical bright red coloration is apparent (Fig. 35.30). Generally, the faster these lesions enlarge, the faster they will involute. This is often clinically evident by the appearance of two signs: fine stellate areas of pale scarring in an area of previous vascularity or the onset of necrosis with skin breakdown. One should be concerned for a constellation of abnormalities called PHACE syndrome when examining a patient with a large plaque-like hemangioma of the face that is over 20 sq. cm² in size. This was first described by Frieden et al. as abnormal arteries, especially those of the central nervous system, coarctation of the aorta, cardiac defects, and unusual ophthalmologic abnormalities can also occur [68]. The ocular abnormalities include the morning glory disk anomaly and microphthalmia. These plaque-like hemangiomas are referred to as segmental hemangiomas , because they form over zones of facial development and not skin dermatomes. Fig. 35.31 depicts a series of patients diagnosed with PHACE after noting large facial hemangiomas. This subject is covered more extensively in Chap. 6.

The lesions are generally unilateral, painless, and compressible with a characteristic spongy feeling on palpation. Deeper subcutaneous involvement changes the color to a more purple tone, although the epidermis still may contain visible, red vascular channels (Fig. 35.32). Isolated eyelid involvement can occur but other facial, forehead, or mucosal lesions may be present (Fig. 35.31). Rarely, significant hematologic sequestering can occur within extensive capillary hemangiomas, especially with visceral lesions, resulting in a bleeding diathesis called the Kasabach–Merritt syndrome [69]. Infantile hemangiomas isolated within the orbit usually show no external features other than proptosis, although globe displacement and restricted ocular motility will also be clues to the presence of a significant orbital component (Fig. 35.33).

With the rapid onset of this condition, deep infantile hemangiomas can mimic the clinical presentation of rhabdomyosarcoma and metastatic neuroblastoma or, if present at birth, a teratoma. Children with metastatic neuroblastoma usually are ill and can have eyelid ecchymosis, which is unusual with infantile hemangiomas. With teratomas, growth can be rapid but usually produces nonaxial proptosis, whereas infantile hemangiomas within the orbit are relatively diffuse and produce mostly axial proptosis. Rhabdomyosarcomas are usually seen in slightly older children, helping to differentiate it from the early onset of infantile hemangioma. In addition, cutaneous color changes with infantile hemangioma and some enlargement with Valsalva maneuvers can help separate infantile hemangiomas from other orbital processes. Combined infantile hemangiomas (involvement on both sides of the orbital septum) merge these features and make up the largest percentage of infantile hemangiomas brought to the attention of the ophthalmologist. Although unusual, isolated conjunctival presentations have the same reddish coloration and enlargement seen with the superficial infantile hemangioma (Fig. 35.34). Some conjunctival involvement is seen in up to one-third of patients with either superficial or combined infantile hemangiomas [70].

Imaging studies have helped to differentiate the orbital components of this entity from other infiltrating orbital processes [71–73]. B-scan ultrasonography demonstrates an irregular mass that blends in with normal orbital structures. Variable internal reflectivity is seen and corresponds to the histology of the hemangioma: solid areas of endothelial proliferation yield low reflectivity, moderate echoes result from ectatic vascular channels, and high reflectivity originates from the fibrous septae in the tumor lobules. CT imaging reveals a diffuse, relatively homogeneous soft tissue mass that usually infiltrates throughout the orbit, although some may be well circumscribed. While this modality is readily available, it should be avoided as it can mislead the physician regarding the possibility of a malignancy. Rather, MRI is a far superior imaging modality for studying orbital vascular tumors. On MRI, high flow rate produces black, serpiginous areas termed “signal voids” on both T ₁– and T ₂-weighted images (Fig. 35.33c). Within the time frame of radio frequency stimulation of the imaged tissue and signal acquisition, the stimulated blood flows out of the vessel and is replaced by nonstimulated blood, which yields no signal and a resultant dark image. The infantile hemangioma is of intermediate signal strength on T ₁-weighted images and appears isointense with brain. On T ₂-weighted images, the hemangioma is relatively hyperintense but maintains a similar intensity to that of brain.

The effects of the infantile hemangioma on visual function and orbitofacial form are why this lesion maintains such high interest among ophthalmologists and primary care practitioners. Amblyopia occurs frequently and can affect as many as 64% of patients with periocular hemangiomas [74]. Astigmatism, anisometropia, strabismus, and sensory deprivation from occlusion can all play a role in amblyopia development due to the direct effects of the infantile hemangioma on the eye. Despite aggressive treatment for both the hemangioma and the amblyopia, Haik et al. found 63% of children (29/46) with periocular infantile hemangiomas have a visual acuity difference greater than two lines between the involved and uninvolved eyes after 5 years of follow-up [75]. They also found that 26% (12/46) had visual acuities of less than 20/200 in the affected eye. Boyd and Collin were able to demonstrate a reduction in the incidence of amblyopia from 80% to 53% when steroid injections were used to treat periocular infantile hemangiomas [74]. Strabismus is seen in approximately one-third of patients, with vertical deviations and esotropias most common [75, 76]. All patients with superficial infantile hemangiomas are left with cutaneous stigmata, including dilated capillaries, “cigarette paper” skin, variable pigmentation, and residual subcutaneous masses from the involuted hemangioma (Fig. 35.35). Proptosis from deep hemangiomas displays a regression pattern that parallels the amount of maximal proptosis: If more than 4 mm of proptosis was present originally, 40% of these patients will have greater than 2 mm or more of residual proptosis [75]. Significant orbital and ocular dystopia may remain from bony expansion or deformity despite tremendous involution of the soft tissue component of the hemangioma (Figs. 35.32 and 35.33).

Infantile hemangiomas show a universal trend toward spontaneous regression that is best termed involution. Although variable in degree, it is evident in virtually every case. The exact mechanism for the initial aggressive growth of these lesions and the resultant involution is not known. Mast cells are seen in high concentrations in proliferating hemangiomas; a 30-fold increase is detectable versus location-matched normal tissues [77]. As the hemangioma involutes, the concentration of mast cells declines and fibroblasts and macrophages can be seen to congregate near the remaining mast cells. Later stages of involution show the formation of cytoplasmic bridges between mast cells and active fibroblasts, intimating that the mast cells recruit and direct fibrosis within the involuting infantile hemangioma [78]. Despite lacking an exact mechanism, resolution of these hemangiomas occurs in 49% of patients by 5 years of age and in 72% by 7 years of age [79]. Margileth and Museles found a similar regression rate of 30% at 3 years of age, 60% by 4 years of age, and 76% at 7 years of age [80]. Fig. 35.36 shows the progression of involution over 7 years in a patient.

The decision to treat periocular hemangiomas is dependent on the consideration of four factors: the location of the hemangioma, the extent of the hemangioma, the degree of amblyopia or the potential for amblyopia development, and the presence of significant systemic hemangiomas. If no signs of amblyopia, anisometropia, severe proptosis with exposure keratopathy, induced astigmatism greater than 1.5 diopters, or total pupillary occlusion are present, reevaluation every 1–3 months is recommended to ensure that no progressive changes occur to induce amblyopia or adversely affect visual development. Despite the lack of ophthalmic indications, treatment may be necessary for periocular infantile hemangiomas if the potential for maceration and erosion of the overlying epidermis exists, which may in turn lead to scarring or infection. Some systemic hemangiomas that require treatment cause obstruction or bleeding in the oral, nasal, or pharyngeal passages and pose breathing or feeding problems for the child.

A variety of treatments are available for infantile hemangiomas. However, oral beta-blockers has been the new goal standard of therapy since 2008 when it was first published as a treatment for severe infantile hemangiomas [81]. While corticosteroids can accelerate the involutional process and may be administered by the oral, injectable, or topical routes, this treatment is a second-line therapy now [82–87]. The systemic treatment of infantile hemangiomas is covered more extensively in Chap. 6, and eyelid involvement is discussed in greater detail in Chap. 23.

In the past, intralesional injection of the steroid has been a popular for infantile hemangioma. This, however, has carried the risk of a retinal vascular occlusion and with the advent of oral and topical beta-blockers has fallen out of favor [81, 88].

Even with a good response to oral beta-blocker, a superficial component to an infantile hemangioma may need additional treatment. Cutaneous hemangiomas have thus been successfully treated with a variety of other modalities. External beam radiation therapy, noncontact Nd:YAG laser, argon laser, continuous wave 577-nm tunable dye laser,carbon dioxide laser, and injections of interferon alfa-2b have been successful in treating infantile hemangiomas [75, 83–94]. This is discussed in further detail in Chap. 6. The noncontact Nd:YAG laser and the argon laser both use thermal injury to the blood vessel as a way to induce vessel closure and lesion involution. The argon laser is absorbed superficially while the noncontact Nd:YAG laser penetrates to a depth of 5–7 mm, yielding greater potential lesion shrinkage. Scarring results from the vessel closure and is somewhat unpredictable with either modality. The carbon dioxide laser coagulates blood vessels in a defocused mode and will create significant scarring if used for the visible surface features of an infantile hemangioma. It has usefulness during surgical resection of residual hemangiomas due to its combination cauterizing and cutting capabilities (see Fig. 35.39). The tunable dye laser operating at 577 nm is selectively absorbed by the beta peak of oxyhemoglobin. Isolated cautery of dermal capillaries can be achieved with short exposures (<10 ms), while adjusting the wavelength to 585 nm coupled with longer exposures can achieve deeper penetration while maintaining vascular selectivity [74].

The surgical excision of infantile hemangiomas is a viable alternative to nonsurgical treatments in hemangiomas that have failed to regress adequately, in those in which visual dysfunction still remains, and in cosmetically unacceptable lesions [95, 96]. Careful surgical excision attempting to debulk rather than completely excise the lesion coupled with clear surgical goals and adequate exposure of the operative area is essential prior to embarking on these sometimes challenging cases, especially if diffuse infiltration of the hemangioma is identified. Isolation and preservation of important normal orbital structures is essential. Preoperative orbital imaging is a necessity to help determine the extent of the lesion and plan the surgical approach (Figs. 35.37 and 35.38). The carbon dioxide laser can be a useful surgical adjunct in helping to limit blood loss, but must be used with care to avoid damaging normal structures (Fig. 35.39). Isolated, small hemangioma of the eyelid can be removed with relative ease (Fig. 35.40) if there is poor response to oral beta-blocker and there is a concern for occlusion amblyopia.