The orbit lies adjacent to the cranial fossa, sinuses, middle face, and upper face. Therefore, the management of complex orbital tumors may require expertise across multiple disciplines. Orbitocranial tumors may arise from the central nervous system and extend into the orbit or vice versa. Endoscopic approaches through the orbit or nasal cavity provide minimally invasive access to the skull base. Orbitosinonasal tumors include malignancies of native sinus tissue. Combined orbital and endoscopic approaches maximize visualization and mobility and minimize morbidity. Orbitofacial cases primarily include the management of advanced cutaneous malignancies. Evolving technologies continue to improve outcomes.
Key points
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Approaches to multidisciplinary orbital tumors can be categorized into orbitocranial, orbitosinonasal, and orbitofacial.
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Incisional and open approaches to orbital tumors have gradually shifted toward endoscopic and minimally invasive approaches when possible.
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There are ongoing imaging and surgical technological developments in the management of complex orbital tumors.
Video content accompanies this article at http://www.advancesinophthalmology.com .
Introduction/history/definitions/background
The orbit is a complex structure wedged between the skull base, paranasal sinuses, and the middle and upper face [ ]. This lends the management of complex orbital pathology, particularly tumors, to subspecialists across various disciplines. The orbital cavity is formed by 7 bones: the frontal, zygomatic, maxillary, sphenoid, lacrimal, ethmoid, and palatine bones, in the shape of a quadrangular pyramid extending posteriorly [ , ]. Anatomic relationships to structures surrounding the orbit often are described in terms of the 4 orbital walls that comprise the pyramidal shape (the medial wall, lateral wall, floor, and roof), which extend posteriorly to meet at the apex. These bones contain and protect the orbital contents, most notably the globe and its supporting structures. The 4 paranasal sinuses (maxillary, frontal, ethmoidal, sphenoidal) are air-filled cavities within the bones after which they are named that approximately line the orbit inferiorly, superiorly, medially, and posteriorly, respectively. The orbit connects to the cranial fossa via the superior orbital fissure, optic foramen, and inferior orbital fissure [ ].
The majority of orbital innervation and vasculature travel through fissures and canals in the apex and supply the various orbital contents, both intraocular and extraocular [ ]. Soft tissues suspending the globe within the orbit include the extraocular muscles and orbital fat, enclosed by the membranous periorbita and orbital septum.
A diversity of tissue type in this anatomically complex space predisposes the orbit to a variety of pathology, both localized and invasive and both benign and malignant [ , ]. Orbital tumors, as compared to other space-occupying lesions such as inflammation, are more likely to require multidisciplinary intervention due to the increased likelihood of growth or invasion into peri-orbital structures [ ]. Orbital tumors are more commonly benign than malignant, with higher rates of malignancy in older patients [ , ]. Many orbital tumors do not require surgical intervention, but this can be necessary when biopsy is needed to make the diagnosis or when orbital dysfunctions, such as optic neuropathy, diplopia, and globe dystopia, are present [ ].
In contrast to intraocular surgery, which was first documented in 800 BC , orbital surgery lacked significant attention until many centuries later [ ]. This is likely due to the infrequency of orbital disease and inaccessibility to all besides dissectors or anatomists, even being referred to as “surgical no man’s land” until the 1940s [ ]. Documented surgical approaches to the orbit date back to the mid eighteenth century with varied techniques to follow including techniques that resemble current approaches such as transconjunctival, transcranial, and transantral, in addition to others that may have inspired modern approaches [ ].
Surgical approaches were methodical but largely experimental until the advent of advanced imaging techniques. While the first intraocular foreign body was identified on x-ray imaging in a patient in Boston in 1898, imaging was not highly influential in the approach to orbital disease until the introduction of coherence tomography (CT), which eventually became instrumental in determining surgical approach [ , , ].
The improved ability to plan preoperatively with new insights into anatomy and, to a limited extent, pathology, provided an informed approach to these complex cases that challenged the previously preferred transcranial approach [ ]. Preoperative planning also facilitated interdisciplinary collaboration to optimize outcomes [ ]. Ophthalmologists now collaborate with subspecialists in otorhinolaryngology, neurosurgery, medical and radiation oncology, and other fields to optimize outcomes in the surgical and nonsurgical management of tumors involving the orbit [ , ].
A variety of surgical approaches can be employed based on surgeon expertise and comfort, anatomic accessibility, and presumed or confirmed histology, with the overarching goal of preserving vision [ ]. Multidisciplinary approaches to the orbit can be grouped anatomically into the following 3 categories: orbitocranial, orbitosinonasal, and orbitofacial. These categories will be defined and discussed in depth.
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Orbitocranial—involving the orbit and cranial fossa, often requiring the combined expertise of orbital and neurologic surgeons.
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Orbitosinonasal—involving the orbit and surrounding paranasal sinuses and nasal cavity, often requiring the combined expertise of orbital and otorhinolaryngologic surgeons.
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Orbitofacial—involving the orbit and the upper or midface, often requiring the combined expertise of orbital, otorhinolaryngologic, and maxillofacial surgeons.
Significance
Key orbitocranial, orbitosinonasal, and orbitofacial tumors and their respective management approaches, with examples, will be outlined. Head and neck cancers are staged with the tumor, node, and metastasis classification by the American Joint Committee on Cancer [ ]. While CT or MRI is mandatory when assessing a tumor, diagnosis is not definitive before histologic evaluation has been performed. Staging has important implications when considering therapy and prognosis [ ].
Orbitocranial tumors
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Tumor types
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Benign
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Meningioma
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Meningiomas arise from the meninges lining the bone. While most are considered benign, they can be associated with significant growth and damage to local structures and can occasionally be malignant.
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The majority of tumors invading the orbit are meningiomas arising from the sphenoid wing (66%) [ ].
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Sphenoid wing meningiomas most commonly present with progressive proptosis and enter the orbit through various methods including directly through the bone [ ].
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Diagnosis is often suggested by CT or MRI with hyperostosis of the sphenoid wing, occasionally with calcification [ ].
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Treatment options include surgery via orbital, cranial, or combined approach (see the following paragraphs) and radiation therapy.
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Unlike many tumors invading the orbit, prognosis of spheno-orbital meningiomas is good with minimal-to-no mortality despite recurrence rates of up to 60% [ ].
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Aneurysmal bone cyst
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These consist of blood lined with a thin wall of bone, most often in children and young adults. While the orbit is an uncommon location, these tumors are rapidly expansile and locally destructive [ ]. Management involves surgery when symptomatic.
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Intraosseous hemangioma
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These are vessel-derived tumors, rare in the orbit but most commonly affect the frontal bone. They are histopathologically differentiated based on the size of the vascular structures involved and typically are managed with surgical excision following preoperative embolization to reduce bleeding [ ].
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Cholesterol granuloma
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An accumulation of blood products, predominantly cholesterol, can persist following hemorrhage. They most often localize to the superotemporal orbit where the largest continuous concave area can facilitate the accumulation of blood via traumatic and physiologic etiologies [ ]. Treatment involves surgical resection.
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Malignant:
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These are tumors arising from the paranasal sinuses (described in greater detail in the orbitosinonasal section)
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Epithelial tumors
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Examples include squamous cell carcinoma (most frequent subtype), sinonasal undifferentiated carcinoma, adenocarcinoma, adenoid cystic carcinoma, small-cell neuroendocrine carcinoma, myoepithelial carcinoma, verrucous carcinoma, basaloid squamous cell carcinoma, lymphoepithelial carcinoma, and so forth [ ].
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Adenoid cystic carcinoma
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These are the most common primary malignant tumors of the lacrimal gland. They are treated with a combination of surgical resection, chemotherapy, and radiation therapy. In advanced cases, management with orbital exenteration and removal of adjacent orbital bone with postoperative radiation may minimize recurrence. These tumors are associated with a poor prognosis with recurrence even years after attempted removal despite often aggressive surgical and adjuvant treatment. Outcomes in children are more optimistic [ ].
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Chondrosarcoma/osteosarcoma
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Imaging reveals calcification [ ].
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It has a survival rate of 79% [ ].
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Management
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Radiation therapy and chemotherapy may be considered when tumors are considered unresectable and/or there is metastatic disease.
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Surgery: Orbitocranial approaches generally involve external open techniques involving bone flaps to provide maximum exposure to the orbit and skull base [ ].
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Surgical approaches ( Figs. 1 and 2 ):
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Frontotemporal approach
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It provides exposure to the frontal and temporal lobes and skull base in addition to the posterior orbit and superior orbital fissure. A modified iteration of the pterional approach extends anteriorly, which is the preferred method of accessing lateral skull-based tumors. This approach is particularly useful in the management of sphenoid wing meningiomas [ ]. While protecting the temporal lobe, the sphenoid wing and crest can be removed to expose the superior and lateral orbit. The anterior exposure is limited by the orbital rim which can be addressed with the orbitozygomatic approach. In rare cases, this method has been described as a method of accessing the contralateral medial and inferior orbit within the intraconal space [ ].
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Orbitozygomatic approach
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This involves potential expansion of the frontotemporal approach, which includes removal of the lateral, superior, and/or inferior orbital rim that provides exposure to the orbit. This method minimizes brain retraction necessary to access tumors deep in the orbit extending into the cranial fossa [ ].
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Supraorbital approach
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Incision occurs through the eyebrow or eyelid and extends laterally with a keyhole. It can include the orbital rim in the bony osteotomy.
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This is a minimally invasive extradural approach that achieves excellent exposure to tumors in the superior and lateral orbit and extends intracranially [ ].
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Unilateral/bilateral subfrontal (transbasal) approach
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It provides exposure to the anterior cranial fossa, superior and medial orbits, and sinonasal cavity [ ].
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A coronal flap is created and propagated inferiorly to expose the nasal bone medially and orbital rim laterally.
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A craniotomy is performed above the orbital rim.
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Several osteotomies are performed to remove the superior orbital rim and expose the anterior two-thirds of the orbital roof.
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Transorbital neuroendoscopic surgery
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Various minimally invasive techniques can access the orbit and skull base with a scope through incisions in the anterior orbit and provide sufficient exposure while minimizing incision size and morbidity [ ].
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The lateral orbital approach with or without bony marginotomy includes the removal of the deep lateral wall to expose the temporal lobe and/or frontal lobe through the orbit.
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The inferior transconjunctival approach can travel along the orbital floor to provide access to the inferior orbital fissure and pterygopalatine fossa.
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Transcaruncular and retrocaruncular approaches provide a medial approach to the optic canal and anterior skull base.
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The superior eyelid crease incision approach is used to access the anterior cranial fossa.
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Fig. 1
Illustration of orbitocranial approaches.
( From Abou-Al-Shaar H, Krisht KM, Cohen MA, et al. Cranio-Orbital and Orbitocranial Approaches to Orbital and Intracranial Disease: Eye-Opening Approaches for Neurosurgeons. Front Surg. 2020;7:1. Published 2020 Feb 7. https://doi.org/10.3389/fsurg.2020.00001 .)
Fig. 2
Illustration of orbitocranial approaches to the intracranial cavity.
( From Abou-Al-Shaar H, Krisht KM, Cohen MA, et al. Cranio-Orbital and Orbitocranial Approaches to Orbital and Intracranial Disease: Eye-Opening Approaches for Neurosurgeons. Front Surg. 2020;7:1. Published 2020 Feb 7. https://doi.org/10.3389/fsurg.2020.00001 .)
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Clinical example: see Box 1 for a surgical case of an orbital tumor requiring transorbital neuroendoscopic resection [ ].
Box 1
Orbitocranial clinical example
In a report by Ramakrishna and colleagues, a 52-year-old man with a history of a right frontal ganglioma managed with surgery and radiation presented with a right orbital mass consistent with a radiation-induced meningioma ( Fig. 3 ) [ ]. Due to previous surgeries, his scalp was poorly vascularized and served as a contraindication to craniotomy-based approaches. A transorbital neuroendoscopic approach was utilized to access and remove the tumor. A precaruncular incision was made, dissection was carried along the posterior medial wall of the orbit, and a small frontal craniotomy was made to access the intracranial tumor. An additional transnasal endoscopic approach was used to remove the tumor ( [CR] ).
Fig. 3
Preoperative coronal, sagittal, and axial coherence tomography (CT) views, as well as a reconstructed surface view with colorized tumor model of a meningioma.
( From Ramakrishna R, Kim LJ, Bly RA, Moe K, Ferreira M Jr. Transorbital neuroendoscopic surgery for the treatment of skull base lesions. J Clin Neurosci. 2016;24:99-104. https://doi.org/10.1016/j.jocn.2015.07.021 .)
Orbitosinonasal tumors
Extension into the orbit has been reported in 35% to 74% of primary neoplasms of the sinonasal cavity. Ethmoid sinus tumors represent 15% to 20% of paranasal sinus neoplasms and often invade the medial wall of the orbit [ ].
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Tumor types:
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Benign:
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Osteoma
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It is the most common benign orbitosinonasal tumor [ ].
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It is most commonly identified in the frontal and ethmoidal sinuses [ ].
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They present with signs of localized mass effect, such as blockage of sinonasal or lacrimal drainage pathways and globe dystopia in over one-third of cases [ ].
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Treatment involves surgical resection when symptomatic.
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Mucocele
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This most commonly involves the ethmoid sinus.
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Mass extends from the sinus into the orbit and presents with mass effect.
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Treatment involves surgical resection when symptomatic.
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Squamous papilloma
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Squamous, or inverted, papilloma are epithelial-derived tumors that arise in the sinuses or the lacrimal sac. Papillomas are benign but may convert into squamous cell or transitional cell carcinoma [ ]. They require local excision.
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Malignant:
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These are squamous cell carcinomas of the sinuses and nasal cavity
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It represents 50% to 80% of all sinonasal tumors [ ].
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It most frequently affects the maxillary sinus (60%–70%), nasal cavity (12%–25%), and ethmoid sinus (10%–15%). These can also affect the nasolacrimal system [ ].
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These can invade into the orbit and cause significant morbidity.
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Surgery involves wide local excision. When the lacrimal sac is involved, surgery often requires dacryocystectomy with medial maxillectomy. Orbital exenteration can be considered in advanced cases. Recurrence rates are high [ ].
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Adenocarcinoma
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It is the second most common sinonasal malignancy. It is derived from glandular origin [ ].
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The majority of cases that invade the orbit are from the ethmoidal sinuses (81%) [ ].
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Sinonasal undifferentiated carcinomas
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These are believed to be of neuroendocrine origin [ ].
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It more frequently occurs in men.
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Imaging typically reveals a large mass with ill-defined margins and areas of necrosis [ , ].
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It has poor prognosis, with survival rates less than 20% over 5 years [ ].
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Non-Hodgkin lymphoma
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These are the most common non-epithelial tumor of the sinonasal cavities, with the B-cell subtype the most common in Western countries [ ].
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Esthesioneuroblastoma
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These are neuroendocrine-derived tumor that arises along the olfactory epithelium with a distinct formation of cysts at the tumor-brain interface [ , ].
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Management:
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This primarily involves surgery with adjuvant chemotherapy and/or radiation therapy. Staging with histologic confirmation and imaging studies are used to estimate the extent of disease and guide treatment approaches. Radiation may occur postoperatively in the case of resectable tumors or weeks prior to resection in the case of larger, more advanced tumor stages that may be more difficult to resect. Surgery is a mainstay of treatment. Chemotherapy is considered in challenging, treatment-resistant, or aggressive cases, and new adjuvant therapies are being studied [ ].
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Surgical approaches
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Endonasal approaches:
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Endoscopic surgical approaches have evolved over the past 30 years. These are utilized for a variety of tumors, particularly those considered high risk via traditional anterior incisional or open neurosurgical approaches [ , ].
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Modern use of the endoscope in orbital cases provides improved visualization and access to posterior structures medially and inferiorly. This strategy minimizes retraction and trauma to orbital structures and may be associated with lower morbidity and shorter hospital stays [ ].
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These are used for a variety of orbitosinonasal tumors, particularly benign tumors.
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Orbital approaches ( Fig. 4 ):
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These involve transcaruncular medial orbitotomy approach to the medial orbit, frontal, ethmoid, and sphenoid sinuses.
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These also involve transconjunctival or subciliary inferior orbitotomy approach to the inferior orbit and maxillary sinus.
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Superior eyelid crease incision approach to the superior and lateral orbit and frontal sinus is another example [ ].
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Combined orbital and endoscopic endonasal approaches can improve the visualization of larger tumors or those that span the orbit and paranasal sinuses. The orbital approach is utilized to dissect and protect orbital structures, while the endonasal approach is used to improve visualization and space for dissection [ , ].
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