Several primary cystic lesions can occur in the conjunctiva (1,2,3,4,5,6,7,8,9,10,11,12,13). Although conjunctival epithelial inclusion cyst is a very common lesion, surprisingly little has been written on this subject and it is only mentioned briefly in textbooks (1,2,3,4). It is usually stationary and recognized readily on slit-lamp examination as a benign cyst. Surgical excision is not recommended. Occasionally a conjunctival inclusion cyst becomes large and symptomatic and extends into the orbit; in these cases, surgical excision is necessary (11,12). In other instances, a conjunctival inclusion cyst can be larger or atypical and the possibility of a neoplasm prompts surgical excision.

Clinically, a conjunctival inclusion cyst is a smooth, thin-walled lesion. It may contain clear or slightly turbid fluid. In some instances, epithelial debris secreted into the lumen of the cyst can deposit inferiorly and assume a “pseudohypopyon” appearance. Particularly in dark-skinned patients, a cyst can be lined with pigment, leading to clinical suspicion of malignant melanoma (5). Conjunctival-orbital cyst has been observed in patients with mucous membrane disorders, like Steven-Johnson syndrome (6).

Although most conjunctival cysts are simple inclusion cysts, there are many causes of a cystic lesion of the conjunctiva, including epithelial implantation cysts from surgical or nonsurgical trauma and parasitic cysts. Some tumors, like lymphangioma and diffuse conjunctival nevus, can be highly cystic. These are discussed elsewhere.

Histopathologically, an epithelial inclusion cyst is usually lined by conjunctival epithelium. The lumen can be clear or it can contain mucinous material, epithelial debris, and occasionally keratin. In some instances, the keratin or sebaceous debris can gravitate inferiorly to form an intracystic “pseudohypopyon.”

In most instances, a conjunctival inclusion cyst can be followed and the lesion may eventually disappear. Larger lesions that produce symptoms or raise suspicion of a neoplasm can be excised locally. Some authors have recommended using indocyanine green solution to facilitate visualization of the cyst during surgery. The prognosis is generally excellent. Sometimes, a cyst may show progressive enlargement and become so extensive that excision may be necessary

Jahnle R, Shields JA, Bernardino V, et al. Pigm ented conjunctival inclusion cyst sim ulating a m alignant melanoma.Am J Ophthalmol 1985;100:483-484.

Organizing hematoma is a circumscribed blood clot that can simulate a pigmented tumor. In the ocular area, the lesion is best known to occur under the periosteum of the orbit, often after overt or occult trauma (1,2,3,4). Although the terms “hematic cyst” or” were previously used by most authors (1,3), it has recently been stressed that, because it lacks a true epithelial lining, the term “cyst” is inappropriate and “organizing hematoma” is the preferred terminology (2). In the conjunctiva, an organizing hematoma can occur spontaneously, after surgical or nonsurgical trauma. Bleeding around an implant for retinal detachment repair can occasionally be confused with conjunctival melanoma (4). Orbital and conjunctival cysts occur occasionally in the anophthalmic orbit following enucleation (5).

Organizing hematoma is often dark in color, suggesting a malignant melanoma. However, it generally lacks feeder vessels or episcleral sentinel vessels.

Histopathologically, an organizing hematoma is a pseudocyst, lined by a pseudocapsule composed of dense fibrous tissue. The central part of the lesion contains breakdown products of blood including cholesterol and a golden-yellow bile pigment called hematoidin (3,4).

Organizing hematoma can be observed if blood is expected. However, if the lesion does not resolve and produces a foreign body sensation or other symptoms, then surgical excision is justified.

Chronic bleeding around a sponge used for retinal detachment repair can simulate a conjunctiva melanoma, as occurred in this 75-year-old man 15 years after retinal detachment surgery.

Lieb W E, Shields JA, Shields CL, et al. Postsurgical hem atic cyst sim ulating a conjunctival m alignant melanoma. Retina 1990;10:63-67.

Several types of foreign body can lodge in the conjunctiva and simulate a neoplasm (1,2,3,4,5). It can result from overt trauma or it can be present without an antecedent history of injury. It is most frequent in carpenters, construction workers, and others with occupations that might subject them to foreign objects. It is important to take a careful history when a foreign body is suspected because the lesion may be noticed many years after the trauma, which may have been forgotten by the patient. Metallic foreign bodies are often dark in color and can be clinically confused with primary acquired melanosis or circumscribed melanoma (1).

A peculiar form of foreign body is the synthetic fiber granuloma (2,3). It results from the implantation of filamentous synthetic fibers in the conjunctival fornix. It is most often seen in infants and young children who sleep in close contact with toys, such as teddy bears, that have synthetic fibers containing titanium, barium, or zinc.

The clinical appearance of a conjunctival foreign body varies with the type of foreign object. Clinically, a metallic foreign body can be black, brown, or gray, suggesting a primary melanoma or extraocular extension of a uveal melanoma. Mascara pigment used to accentuate the eyelashes can rarely imbed in the conjunctiva and simulate a melanoma (4). It is an irregular mass that appears to contain hairs, sometimes suggesting a dermoid, dermolipoma, or caterpillar hairs. However, the hairlike structures are actually synthetic fibers from the toy.

The pathology of a conjunctival foreign body necessarily varies with the type of object. Most foreign bodies are birefringent with polarized light. With regard to the synthetic fiber granuloma, the hairlike fibers induce an intense granulomatous inflammatory reaction with foreign body giant cells surrounding the foreign material.

Treatment is generally surgical removal. A small, asymptomatic foreign body can be observed without surgical excision.

M iscellaneous foreign m aterials can occur in the conjunctiva and sim ulate a neoplasm . Unusual exam ples are show n of synthetic fiber granulom a, M IRAgel retinal detachm ent im plant, and m ascara sim ulating m elanom a.

1. Shields JA, Augsburger JJ, Stechschulte J, et al. Synthetic fiber granuloma of the conjunctiva. Am J Ophthalmol 1985;99:598-600.

2. Shields CL, Demirci H, Marr BP, et al. Expanding MIRAgelT scleral buckle simulating an orbital tumor in 4 cases. Ophthal Plast Reconstr Surg 2005;21:32-38.

3. Shields JA, Marr BP, Shields CL, et al. Conjunctival mascaroma masquerading as melanoma. Cornea 2005;24:496-497.

Episcleritis and scleritis can be elevated and vascular, and simulate an amelanotic conjunctival neoplasm, particularly conjunctival squamous cell carcinoma. Nodular episcleritis is a benign, often painful inflammatory condition. It is idiopathic in most instances, but can be related to several inflammatory conditions, including rheumatoid arthritis. It lasts about 2 to 3 weeks, after which it spontaneously resolves. It has a tendency to recur.

The acute onset and progression and the associated pain are usually sufficient to differentiate episcleritis from a primary neoplasm, which is usually nonpainful and more slowly progressive. One tumor that can have a similarly rapid onset and pain is metastatic carcinoma to the conjunctiva, which is a rare condition. Episcleritis can be localized (nodular) or diffuse (1).

Scleritis is often a deeper inflammation that may be granulomatous or nongranulomatous in nature. Almost half of affected patients will be found to have other systemic disease, particularly connective tissue disease such as rheumatoid arthritis. Other cases remain idiopathic despite systemic evaluation (2). Scleritis can lead to scleral necrosis and secondary uveal staphyloma. The typical appearance and associated systemic findings should help to differentiate scleritis from neoplasm. In some instances, however, a necrotic intraocular melanoma can produce secondary inflammation of the sclera and adjacent tissues. Hence, a patient with scleritis should undergo a fundus examination to exclude the possibility of an intraocular neoplasm.

Depending on the state of the disease, episcleritis or scleritis can have acute or chronic inflammatory cells and may have signs of granulomatous inflammation with epithelioid and giant cells.

The patient with suspected episcleritis should be evaluated for the known causes of inflammation, such as rheumatoid arthritis and other known granulomatous inflammations. If the lesion does not resolve on systemic or topical corticosteroids, then excisional biopsy may be warranted.

Churg-Strauss syndrome is an uncommon systemic disease characterized by asthma, eosinophilia, and vasculitis (1,2,3,4,5,6). Systemic involvement can lead to renal and cardiac failure as well as peripheral neuropathy, and often has a fatal outcome. The differentiation of Churg-Strauss syndrome from vasculitides like Wegener’s granulomatosis and periarteritis nodosa have been described (2). Conjunctival involvement is now known to be a feature of Churg-Strauss syndrome, in which case it can simulate a neoplasm (2,3,4,5,6).