Benign spindle cell tumor of the male breast

Benign spindle cell tumors of the male breast are definitely rare. They have a subareolar localization and are circumscribed but not encapsulated. Ultrastructurally the neoplasm consists of histiocytic cells, fibroblasts, myofibroblasts and their transitional stages. Myoepithelial cells or smooth muscle cells are lacking. Although myofibroblasts contain lots of filaments, aniline reaction, PTAH stain and iron hematoxylin impregnation remain negative.