Two cases of desmoplastic trichoepithelioma.
Desmoplastic trichoepithelioma is a rare tumor that usually exhibits the distinct clinical features of a solitary granuloma annulare-like growth on the face. We experienced two cases of desmoplastic trichoepithelioma, one of which showed unusual clinical features and the other of which was a typical case. The first case was a 20-year-old female who presented with a five year history of a solitary yellowish nodule, 5 mm in diameter, centrally between the eyebrows. There was no central dimple or elevated border. The other case was a 40-year-old female who presented with a ten year history of a solitary nodule, 6 mm in diameter on her left cheek. The latter lesion had a typical depressed area in the center of the nodule with elevated borders and could be clinically diagnosed as desmoplastic trichoepithelioma. The histopathological examination revealed that both of them were desmoplastic trichoepithelioma. Histopathological comparison of the two specimens suggested that the clinical dimple in the center of the first tumor might be the result of stromal dystrophic changes induced by the tumor.