Primary primitive neuroectodermal tumor of the breast.

Peripheral primitive neuroectodermal tumors (PNETs) are small, round, blue cell, sarcomatous neoplasms of the bone and soft tissues that arise from neuroectodermal elements and primarily occur in children and adolescents. In adults, they are extremely rare and have been reported in the chest wall (Askin tumor) and other visceral sites.(1-6) To our knowledge, a primary breast PNET has not been reported.(1) We present a case of a primary breast PNET that was initially confused with an epidermal inclusion cyst.