Clinicopathological mimics of accessory breast tissue: a case series with cytological and histological correlation

Axillary swellings in young women present a broad differential diagnosis, from benign developmental anomalies such as accessory breast tissue (ABT) to neoplastic lesions including fibroadenoma and phyllodes tumor. This case series reports eight patients with varied clinical and pathological findings. Six women aged 19–28 years presented with unilateral or bilateral axillary swellings, with initial clinical impressions ranging from lipoma and lymphadenopathy to soft tissue tumors. Fine needle aspiration cytology (FNAC) was performed in all cases, followed by surgical excision and histopathological confirmation in most. Diagnoses included ABT in four patients, lactating adenoma in one, bilateral lipomas in one, benign phyllodes tumor in one and fibroadenoma in one. FNAC aided in narrowing the differential diagnosis, but definitive identification relied on excision and histopathology. Recognition of ABT and its mimickers is important, as these lesions can undergo physiological and pathological changes similar to normal breast tissue and misdiagnosis may lead to unnecessary anxiety or inappropriate management. This series highlights the value of correlating clinical, cytological and histopathological findings to ensure accurate diagnosis and optimal treatment of axillary swellings in young women.