A Rare Case of Conjunctival Pseudoglandular Hyperplasia Identified During Mohs Micrographic Surgery of an Infraorbital Basal Cell Carcinoma.

A 38-year-old white male presented for Mohs Micrographic Surgery (MMS) consultation with a biopsy proven basal cell carcinoma (BCC) on the right infraorbital cheek encroaching upon the lower eyelid. During MMS, glandular proliferation and goblet cell hyperplasia were visualized on histologic sections, raising concern for an adnexal or mucinous carcinoma. Following referral for expert dermatopathological consultation, a final diagnosis of pseudoglandular hyperplasia of the conjunctiva (PHC) in the setting of chronic conjunctivitis was made, likely having developed in response to longstanding irritation from the nearby BCC. This case represents only the sixth reported case of PHC in the literature and the first identified incidentally during MMS of an adjacent cutaneous neoplasm. PHC is an uncommon, benign reactive proliferation characterized by invagination of the conjunctival epithelium into the stroma, forming gland-like structures. Due to its histological resemblance to invasive neoplasms, such as mucoepidermoid carcinoma, PHC poses a significant diagnostic and clinical conundrum. Only a handful of cases of PHC have been described and a diagnostic framework has yet to be sufficiently established. This report highlights the importance of increasing the awareness of this benign phenomenon and defining its histologic features to distinguish it from resemblant malignancies and avoid unnecessary surgery.