Verrucous trichoadenoma

Two cases of verrucous trichoadenoma are reported. Clinically, both lesions were diagnosed as seborrheic keratoses, but histopathologically no areas of basaloid cell proliferation were seen in the numerous sections and there were many small, epidermoid cysts in the dermis which contained one or more vellous hairs. Some of these cysts expelled their horn material into the surface keratin layer in a "boiling pattern". We propose the term "verrucous trichoadenoma" for these tumors.