Clear cell hidradenoma
A 31-year-old man presented with a solitary, asymptomatic 2 × 2.5 cm nodule on the occiput region of the scalp. About 2 years ago, the patient noticed a papule in this area, but due to being small and without symptoms, no action for diagnosis and treatment was taken. About 4 months ago, the lesion has started to grow quickly and gradually had become a 2 × 2.5 cm nodule [].\nThe lesion was cone shaped with a small ulcer and little discharge in the apex. Lesion was asymptomatic but because of recent rapid growth and location of the tumor that touch pillow during sleep, has found a little pain and burning. The lesion was sampled, and after confirmation of diagnosis complete elliptical excision was performed and resent to pathology [Figures and ].\nMacroscopic examination specimen consisted of skin-covered mass measuring 2.5 × 2 × 1.5 cm3. It was firm in consistency. The cut surface was grayish white and homogenous.\nMicroscopic examination the histopathological examination of the specimen showed similar morphology. The dermis showed tumor lobules composed of cellular masses separated by eosinophilic, homogenous material [].\nIn solid portions of the tumor, two types of cells could be recognized. One cell type is polyhedral with a rounded nucleus and slightly basophilic cytoplasm. Another cell type was usually round and contains very clear cytoplasm, the cell nucleus appears small and dark [].\nNo atypical mitotic figures were noticed. The diagnosis of clear cell hidradenoma or nodular hidradenoma was made.