Villous Sebaceous Adenoma Arising from the Caruncular Surface Squamous Epithelium

Abstract

• Benign and malignant sebaceous cell tumors are both known to originate in the caruncle. • These tumors typically grow in nests and lobules in the caruncular stroma. • Sebaceous tumors arising from the surface non-keratinizing squamous epithelium of the epibulbar and tarsal regions have been reported. Novel Insights • A caruncular sebaceous adenoma originated from the surface squamous epithelium which displayed focal sebaceous cell differentiation. • The pattern of growth was most unusual and consisted of multiple invaginated crypts with intervening finger-like villi. • Lateral lobular sebaceous lobules originated as outgrowths from the crypts and were mostly responsible for the widening of the stroma between the crypts. • p16 nuclear and cytoplasmic positivity indicated a possible causative role for high-risk human papilloma virus, while immunohistochemical results for intact mismatch nuclear repair proteins ruled out an association with the Muir-Torre syndrome.