Aggressive breast fibromatosis with axillary accessory breast mastitis mimicking carcinoma: a case report

Aggressive fibromatosis, also referred to as desmoid-type fibromatosis or desmoid tumor, is an uncommon locally invasive tumor with a high local recurrence rate. It rarely occurs in the breast and the etiology of aggressive breast fibromatosis is still unknown but may be related to previous mammary trauma or surgery. Preoperative diagnosis of aggressive breast fibromatosis is still a challenge for clinicians. The optimal treatment for the disease is still controversial, but wide surgical excision with negative margins is considered the standard option. We report a 28-year-old woman of aggressive breast fibromatosis accompanied with accessory breast mastitis in her ipsilateral axilla. The lesions imitated breast carcinoma with axillary lymph node metastasis due to their similar clinical and imaging manifestations. Her mammary mass finally underwent wide surgical excision, and negative margins were confirmed during the surgery. To our knowledge, this is an extremely rare case accompanied with axillary accessory breast mastitis and will contribute to the management of aggressive breast fibromatosis.