Conjunctival Biopsy - Sebaceous Carcinoma

Sebaceous carcinoma is the second most common malignancy of the eyelid (basal cell carcinoma is the most common malignant eyelid tumor).

Sebaceous carcinoma may spread into the conjunctiva and may generate the clinical appearance of a blistering condition such as pemphigoid. Histologically, intraepithelial sebaceous carcinoma in the conjunctiva may mimic pemphigoid. Ophthalmologists should be particularly cautious in making the diagnosis of unilateral pemphigoid (sebaceous carcinoma is usually unilateral -- pemphigoid is usually bilateral!). As always, ophthalmologists should be gentle in handling the tissue and prepare the specimen properly for submission to the laboratory.

Once the diagnosis of sebaceous carcinoima is established in the eyelid, the ophthalmologists may take non-directed conjunctival biopsies to map the presence of conjunctival involvement by tumor.

Pathologists should note that the appearance of sebaceous carcinoma in the conjunctiva mimics squamous epithelial dysplasia or carcinoma in situ. Look for foamy cytoplasm and smudged basophilic nuclei. Mitotic figures may be abundant and are often atypical.

Sebaceous carcinoma involving the conjunctiva. This condition may mimic squamous epithelial dysplasia or carcinoma in situ histologically.