Extra-abdominal fibromatosis: Clinical and therapeutic considerations based on an illustrative case.

Extra-abdominal fibromatosis is a rare, benign disease that is characterized by a local but not metastatic invasivity. In particular, desmoid tumors of the chest wall represent only 10-20% of all deep fibromatoses. The disease occurs more often in females and has a higher incidence between puberty and the fourth decade of life. The present study reports the case of a 34-year-old female who came to our attention due to a voluminous mass in the right subcostal region. The magnetic resonance imaging of the upper abdomen confirmed the presence of a neoplasm localized between the anterior hepatic margin and the right costal plane. Through a right subcostal laparotomy, the voluminous 95×45×94-mm neoplasm was excised. Histological examination showed evidence consistent with extra-abdominal fibromatosis. The patient has not shown recurrence of the disease for 4 years since the surgery. Overall, radical surgery with disease-free resection margins is the prime treatment option for this disease. Other therapeutic options, such as radiotherapy, hormonal therapy or treatment with imatinib mesylate, can also be considered in certain cases.