Benign adnexal tumor with follicular differentiation

Multilobulated dermal nodule composed of nests of basaloid cells

Well-circumscribed, non-encapsulated nodule

Nests of basaloid cells with peripheral palisading

It should be noted that there are no artifactual retraction clefts (clear spaces) at the periphery of the nests, which distinguishes it from basal cell carcinoma.

Many trichoblastomas are erroneously diagnosed as basal cell carcinomas, explaining the overestimation of the incidence of basal cell carcinoma occurring within a sebaceous nevus.

LEGEND

LEGEND

Trichoblastoma is the main tumor occurring within a sebaceous nevus; although difficult to appreciate in the current images, this is indeed a trichoblastoma associated with a sebaceous nevus.