CONJUNCTIVAL EPITHELIAL TUMORS
Sarah E. Coupland • Jakub Khzouz • Raymond Barnhill
SQUAMOUS EPITHELIAL LESIONS
Pseudoepitheliomatous hyperplasia (PEH) is a rare benign epithelial proliferation of the conjunctiva or cornea developing in response to trauma or inflammation. Although a benign reactive process, PEH may closely resemble squamous carcinoma clinically, and thus histopathological examination is often required in order to exclude malignancy.1
PEH often presents clinically as “leukoplakia” or a “limbal mass.”
Microscopic examination reveals epithelial hyperplasia with normal maturation and keratinizing squamous metaplasia of the conjunctiva. There is no significant cellular pleomorphism or dysplasia.2 The underlying conjunctival stroma may show chronic inflammation (Fig. 39-1).
Pseudoepitheliomatous hyperplasia. Epithelial proliferation with normal maturation and no dysplasia.
The differential diagnosis includes squamous papilloma and conjunctival squamous intraepithelial neoplasia. The latter shows significant epithelial dysplasia and pleomorphism (see below).
Squamous papilloma (SP), the most common conjunctival tumor, is a benign exophytic lesion composed of a finger-like projection of conjunctival squamous epithelium lining a fibrovascular core.
This entity occurs most frequently in young men 20–39 years of age (Table 39-1).3-6 Clinically, it presents as a single exophytic sessile or pedunculated red mass, most commonly located medially and inferiorly on the conjunctiva.3 In children, papillomas are small and often multiple.4 Infection with human papilloma virus (HPV; most commonly HPV 6 and 11) is strongly associated with the development of SP.5 Frequently relapsing lesions are associated with HIV infection. Conjunctival papilloma often shows spontaneous regression after years of presentation; however, recurrence frequency is 11%.3 Development of severe dysplasia or invasive carcinoma is a rare event in a papilloma6 but must be excluded.
TABLE 39-1Squamous Papilloma |Favorite Table|Download (.pdf) TABLE 39-1 Squamous Papilloma
|Clinical Features |
|Any age, young men most common: 20–39 years |
|Most common conjunctival tumor |
|Medial or inferior conjunctiva |
|Single or multiple lesions (common in children or immunosuppressed patients) |
|Exophytic, sessile, or pedunculated reddish mass |
|Most cases associated with human papilloma virus (HPV) (most commonly HPV 6 & 11) |
|Histopathologic Features |
|Exophytic, digitate, sessile, or inverted growth pattern with fibrovascular core |
|Hyperkeratosis overlying acanthotic or thinned conjunctival squamous epithelium with varying numbers of goblet cells |
|Koilocytic changes may be present in squamous epithelium |
|Epithelial dysplasia, may occur, usually mild |
|Differential Diagnosis |
|Squamous cell carcinoma invasive (particularly confused with inverted papilloma) |