Peripheral Primitive Neuroectodermal Tumor of Breast.

Peripheral primitive neuroectodermal tumor (PNET) is a malignant tumor of the young, usually found in bony structures. It is extremely rare to find it in the breast. Only 9 cases have been reported in the medical literature. A 35-year lady had a painless lump in upper left outer quadrant of her left breast which appeared as a BIRADS III lesion on mammography. However, biopsy and later surgery was done on clinical grounds. Histopathology and immunohistochemistry diagnosed a PNET tumor. It had recurred 8 years after surgery and required chemotherapy.