Teaching Case 28

42 y/o F presents with a palpable abnormality in the left breast. What is the most likely diagnosis?

fibromatosis 2


  • Extra-abdominal desmoid tumor of the breast; rare
  • Tends to occur in close proximity to pectoral muscles
  • Associated with: 
    • Gardner syndrome
    • Breast implants
    • Prior surgical trauma
  • Tx: Wide local excision (locally aggressive)
  • Recurrence rates high (20-30%)

Related Radiology Article: Winkler N, Peterson M, Factor R. Breast Fibromatosis: Radiologic–Pathologic Correlation. Journal of Breast Imaging. 2021 Sep;3(5):597-602.