A case of adamantinoid basal cell epithelioma

A 56-year-old woman visited the clinic of dermatology, Yokohama Sakae Kyosai Hospital in May of 1992 with a 5-year history of a blue-gray lesion on her left cheek which had enlarged asymptomatically. The tumor was excised with Z plasty closure. Histopathologically, a loosely encapsulated tumor was situated in the upper to deep dermis. At the periphery of the tumor, there were typical solid basal cell epithelioma (BCE) nests, but within the majority of lobules, intercellular spaces were widened and cells were connected by stellate appendages. Mucoid material filled the spaces and the cells at the periphery palisaded. Histochemical study revealed that the mucoid substance contained hyaluronic acid. An immunohistochemical study was performed using peroxidase antiperoxidase (PAP) method. The antibodies used were anti-epithelial membrane antigen (EMA), anti-carcinoembryonic antigen (CEA), anti-S-100 protein, anti-neurofilament, anti-vimentin, anti-desmin, anti-BRST-1, and anti-BRST-2. The tumor cells and stroma expressed none of these antigens. The tumor was diagnosed as an adamantinoid BCE.