Diagnostic puzzle—a case of an axillary soft tissue granular cell tumor mimicking a breast cancer lymphadenopathy: diagnostic challenge and surgical treatment

Granular cell tumor (GCTs) is a rare soft tissue neoplasm of neural origin, often challenging to diagnose at first presentation due to its resemblance to other lesions and pathologies. Axillary localization poses a particular diagnostic challenge because of its potential to mimic lymphoproliferative disorders or metastatic breast disease. Accurate identification is crucial to avoid inappropriate treatment. We report the case of a 33-year-old Nigerian woman who presented with a painless, palpable mass in the left axilla, initially suspected to be an abnormal lymphadenopathy. Ultrasound and magnetic resonance imaging (MRI) revealed a well-circumscribed soft tissue lesion, making direct assessment essential for a definitive diagnosis. Complete surgical excision was performed. Final histopathological evaluation confirmed a benign granular cell tumor with negative surgical margins. The postoperative course was uneventful, and no recurrence was observed during follow-up. This case highlights the importance of including granular cell tumor in the differential diagnosis of axillary masses. A multimodal diagnostic approach, incorporating imaging and histopathological confirmation, is essential for accurate diagnosis and appropriate treatment planning. Conventional open surgery remains a highly reliable and effective approach for achieving the best curative and prognostic outcome.