Granular cell tumor of the breast in a male. A case report.

Background: Granular cell tumor (GCT) is a rare tumor of the soft tissues; the most common site of occurrence is the tongue. The diagnosis of GCT is fairly straightforward on both fine needle aspiration cytology and histopathology. Occasionally the tumor's presence in an unusual site may create confusion with carcinoma, especially when it occurs in the breast, where carcinoma is more common.
Case: A case of GCT occurred in the breast of a male with simultaneous detection of the same type of tumor in the soft tissues of the upper arm and back. The diagnosis was made on a fine needle aspirate of the breast mass, which demonstrated characteristic diastase-resistant, periodic acid-Schiff-positive intracytoplasmic granules.
Conclusion: The breast, especially in males, is an unusual location for GCT. Clinicians and pathologists must be alert, therefore, to its existence and its inclusion in the differential diagnosis of tumors of the breast.