Granular cell tumor of the male breast: a case report and review of the literature

Abstract

Background: Granular cell tumors (GCTs) of the breast are rare tumors that originate from Schwann cells. They are most common in premenopausal females of African descent, and fewer than 30 cases of GCT in males have been described in the literature. Most prior cases of male breast GCTs presented as symptomatic palpable masses in the breast that are subsequently excised. In this case, we describe a rare asymptomatic presentation of male GCT that was completely excised on core needle biopsy and found to be associated with a granuloma after excisional biopsy, the first case reported in the literature. Case Description: A 56-year-old African American male with a history of hypertension, alcohol abuse, atrial fibrillation, heart failure, diabetes, and pancreatitis incidentally found to have a mass in his right breast while undergoing diagnostic imaging workup for a mass in his contralateral breast. Biopsy revealed a GCT, positive for S-100 and CD68. He underwent excisional biopsy of his GCT, the lesion was completely excised, and he is recovering well with no evidence of recurrence at 6 months. Conclusions: GCTs of the male breast are rare entities that present diagnostic and therapeutic challenges for providers and mimic breast carcinomas. The pathophysiology of GCTs is unknown, and several risk factors are postulated to play a role in development of GCTs, such as gynecomastia and alcohol abuse in this patient. This case provides further insight into the factors leading to development of male breast GCTs, and details appropriate diagnosis and management of this disease.