Malignant granular cell tumor of the breast.

A primary malignant granular cell tumor (MGCT) in the breast is presented. The tumor showed mitoses, pleomorphism, necrosis and regional lymph node spread. While local excision is the best form of treatment, MGCT can spread rapidly to lymph nodes, lungs, liver, and bone. This lesion is an uncommon primary malignancy of breast with only 4 other cases reported.