Case report of a benign granular cell tumor mimicking carcinoma of the breast in a young woman: a diagnostic challenge

Introduction: Granular cell tumors (GCTs) are rare, low-grade Schwann cell tumors found in the skin, soft tissue, and mucosal surfaces of the oral, gastrointestinal, and respiratory tracts. 1 in 1000 breast cancer cases is GCT. Just 1%–2% of GCTs are malignant granular cell tumors (MGCTs). Case Presentation: Herein we introduce a 34-year-old woman with a palpable mass that was confirmed to be GCT by pathology. Discussion: Benign GCTs are described as having an absence of necrosis, vesicular nuclei with large nucleoli, a high nuclear to cytoplasmic ratio, pleomorphism, spindling tumor cells, and an accelerated mitotic rate greater than 2 mitoses per 10 high power fields. GCTs of the breast typically present as solitary, palpable, painless masses and are typically located in the upper-inner quadrant along the distribution of the supraclavicular nerve. Since benign GCTs do not spread to regional lymph nodes, axillary staging is unnecessary. The probability of local recurrence is between 2 and 8% with negative surgical margins and above 20% with positive surgical margins; nevertheless, recurrence of benign GCTs does not predict a bad prognosis. Conclusion: Identifying granular cell tumors of the breast is essential for avoiding invasive procedures and radical surgeries.