Primary bulbar conjunctival basal cell carcinoma: A clinical-pathologic report and literature review.

Purpose: To enhance the characterization of primary bulbar conjunctival basal cell carcinoma (BCC) clinically and histologically, via report of a case and review of the relevant medical literature. Observations: We report the case of a 73-year-old man with no history of skin cancer who presented with a bulbar conjunctival nodule without connection to the eyelid or caruncle, originally thought to represent a pyogenic granuloma. After one month without improvement on topical prednisolone, excisional biopsy was performed, with routine histopathology and immunohistochemistry. The tumor was found histologically to be primary conjunctival BCC. Immunostaining exhibited negative Ber-EP4 and S100, mostly negative CK7 and EMA, and positive p63. Margins were negative, and the patient had no recurrence six months after excision. Conclusions and Importance: Primary conjunctival BCC must be considered in the differential diagnosis of a conjunctival lesion which may initially appear benign but does not behave as expected clinically. The location of the tumor in the case presented here refutes a prior postulate that primary conjunctival BCC arises from basal adnexal epithelium in the caruncle. Of the immunohistochemical findings, only the Ber-EP4 result differed from the typical immunostaining profile of cutaneous BCC. Further study is needed to determine the frequency of Ber-EP4 positivity in primary conjunctival BCC.