Basaloid follicular hamartoma: clinical, dermoscopic, and histopathological characteristics of case.

Basaloid follicular hamartoma (BFH) is a rare benign adnexal tumor with variable clinical presentation. We report a case of a 64-year-old man, who presented with an incidental finding of a 3mm hyperpigmented macule on his cheek. Dermoscopy revealed a structureless blue lesion. Histopathology examination showed interconnecting lobules and cords of bland pigmented epithelial cells within the dermal stroma, with the presence of pseudohorncysts. The lesional cells were faintly positive for Bcl2on immunohistochemical staining. These findings were consistent with basaloid follicular hamartoma. Histological differential diagnoses include benign lesions such as trichoepithelioma, and malignant lesions such as basal cell carcinoma (BCC).