A large and aggressive fibromatosis in the axilla: a rare case report and review of the literature

Mingyue Duan,1 Hua Xing,1 Keren Wang,1 Chunbo Niu,2 Chengwei Jiang,2 Lijuan Zhang,1 Shereen Ezzat,3 Le Zhang1 1Department of Breast Surgery, China-Japan Union Hospital, Jilin University, Changchun, Jilin, People’s Republic of China; 2Department of Pathology, China-Japan Union Hospital, Jilin University, Changchun, Jilin, People’s Republic of China; 3Ontario Cancer Institute and The Endocrine Oncology Site Group, Princess Margaret Hospital, University Health Network, Toronto, ON, Canada Abstract: Aggressive fibromatosis (AF) is a rare benign tumor, which occurs in the deep part of bone and muscle fibrous tissue. Clinical and pathological features can be challenging for definitive diagnosis. Here, we report a rare case of a large AF in the axilla. Interestingly, 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography showed significant increase in standard uptake value. Surgical resection yielded a spindle cell tumor likely of fibromatosis origin which was positive for β-catenin expression. Keywords: aggressive fibromatosis, desmoid-type fibromatosis, axilla, 18 F-fluorodeoxyglucose, PET/CT, β-catenin