Intranasal dermal analogue tumor (membranous basal cell adenoma). Ultrastructure and immunohistochemistry.

To our knowledge, this is the first case of an intranasal monomorphic salivary gland adenoma (dermal analogue type) arising in a man exhibiting the salivary gland-skin adnexal tumor diathesis. Ultrastructurally, this tumor is composed of cells displaying squamous, secretory, luminal, and, very rarely, myoepithelial differentiation. Additionally, this is the first ultrastructural demonstration of intralobular Langerhans' cells in a dermal analogue tumor from any site. These Langerhans' cells can be demonstrated histologically by S-100 protein immunostaining. Epithelial tumor cells per se display no glial fibrillary acidic protein immunoreactivity, but rare epithelial cells stain faintly for S-100 protein. These findings seem to be distinct from pleomorphic adenoma and adenoid cystic carcinoma, the principal histologic differential diagnosis.