A Case of Trichoblastoma

Trichoblastoma includes all benign follicular germinative cell tumors in skin. We presented a case of trichoblastoma which occurred on the scalp as a large pedunculated tumor. The tumor was composed of lobular aggregations of basaloid epithelial cells and numerous primitive papillary mesenchymal bodies. Stromal retraction was observed between the stroma adjacent to epithelial nests and surrounding normal dermis. Focal connection to the overlying epidermis was observed. The classification and terminology for the benign neoplasms with follicular differentiation was discussed.