Axillary fibroadenoma: A rare case report and review of literature

Fibroadenoma (FA) is a common benign tumor of the breast, but its occurrence in the axillary region is exceptionally rare. Such lesions may arise from accessory breast tissue or develop de novo within axillary stromal tissue, often mimicking lymphadenopathy or other soft-tissue masses. This report presents a rare axillary FA in a young female, highlighting its unusual site and diagnostic importance. A 23-year-old woman presented with a painless swelling in the left axilla that had gradually increased in size over 5 months. Ultrasound showed an oval, heterogeneously hypoechoic axillary mass with macrolobulated and angular margins, categorized as BI-RADS 3. Ultrasound-guided core needle biopsy and subsequent excision confirmed a fibroadenoma arising from accessory breast tissue, with an uneventful postoperative course and no recurrence at 17 months. A review of the published literature identified 13 cases of axillary fibroadenoma across 12 reports, in women aged 16-41 years. Most were premenopausal (76.9%), right-sided lesions predominated (46.2%), and ultrasound was the most common imaging modality (69.2%). Histopathology confirmed fibroadenoma in all cases, the majority arising from accessory breast tissue, and surgical excision was the usual treatment, with no reported recurrences. Axillary FA is a rare benign lesion of young women. Despite its resemblance to other axillary masses, histopathological confirmation is crucial, and complete excision ensures an excellent prognosis with minimal recurrence risk. On ultrasound, an axillary fibroadenoma can closely mimic a lymph node, so recognition of this appearance is essential to reach an accurate diagnosis and avoid unnecessary intervention.