Spiradenocylindroma: Morphology of a Rare Hybrid Adnexal Tumor.

Spiradenocylindroma is a rare benign adnexal tumor with features of both spiradenoma and cylindroma, the scalp and face being the most common sites. They are considered to arise from pluripotent cells of abortive adnexal primordial tissue. Fine needle aspiration cytology, along with cell block, can give clues regarding the diagnosis. The final diagnosis is made on histopathology, which shows features of both cylindroma and spiradenoma in the same tumor. Multiple spiradenocylindromas can be associated with Brooke-Spiegler syndrome, where malignant transformation has also been reported. We report a case of spiradenocylindroma of the arm in a 50-year- old male and describe the clinical, cytologic, cell block, and histopathologic features.