Incidental Detection of an Extra-abdominal Desmoid Tumor of the Axilla: A Case Report

Desmoid fibromatosis is a rare, benign but aggressive tumor of mesenchymal origin. Its main characteristic is local infiltration and a high likelihood of recurrence. Desmoid tumors can occur either sporadically or in a familial form (familial adenomatous polyposis (FAP)). Depending on their location, they are classified as superficial or deep, such as masses in the abdominal wall, extra-abdominal, or intra-abdominal tumors. Rarely, they can be found in the axillary area. We describe a case of a 69-year-old female presenting with a mass in her left axilla that was biopsy-proven to be a desmoid tumor.