Fibromatosis arising from the pectoralis major muscle mimicking breast cancer

• Main Authors: Laryn Steadman, BFA, Susan Crook, MD
• Format: Article
• Language: English
• Published: Elsevier 2018-12-01
• Series: Radiology Case Reports
• Online Access: http://www.sciencedirect.com/science/article/pii/S1930043318302668

Fibromatoses are soft tissue tumors composed of fibroblasts which commonly appear in the muscular aponeurosis of the abdomen. Mammary fibromatoses occur in only 0.2% of breast neoplasms and have been reported in association with prior breast augmentation and Gardner's syndrome. Multiple imaging modalities have been used to characterize the appearance of breast fibromatosis; however, it remains a tissue diagnosis given the variability both within and across modalities. We present the case of a 25-year-old female with a history of palpable breast mass who was evaluated with ultrasound, diagnostic mammography, MRI, and CT. Ultrasound-guided biopsy revealed fibromatosis, and MRI ultimately revealed that the mass was arising from the pectoralis major muscle and extensively involved the chest wall. Keywords: Fibromatosis, Mammary fibromatosis, Chest wall, Pectoralis