Membranous basal cell adenoma arising in the eyelid.

Basal cell adenoma (BCA) is a specific entity that lacks the myxochondroid stromal component of pleomorphic adenoma. Membranous basal cell adenoma is a rare variant of BCA, which is characteristic by abundant eosinophilicextracellular hyaline material deposited either inside or at the periphery of the epithelial islands. Herin we describe the first case of membranous BCA arising in the upper eyelid in a 38-year-old woman. A well-demarcated nodule arising in the eyelid was composed of isomorphic basaloid cells organized with a prominent basal cell layer and distinct basement membrane-like material. Immunohistochemically, S100 protein and p63 highlighted the basal aspect of the peripheral epithelial cells, while CK7 expressed on the luminal cells. A diagnosis of membranous basal cell adenoma of the eyelid was made. At follow-up for 2 years and 3 months later, there was no evidence of recurrence. Further pathological characteristics of this disease are discussed.