Retroperitoneal desmoid tumor in a patient with familial adenomatous polyposis: A case report

Desmoid tumors are benign fibroblastic neoplasms, with locally invasive features and a tendency of recurrence. They are considered an aggressive non-metastatic fibromatosis. The retroperitoneal location is extremely rare. Their exact mechanism of occurrence is still controversial, but could be related to a genetic predisposition, hormonal factors or traumatic factors, including surgery. This entity faces management difficulties due to its rarity, the variable circumstances of its discovery, and the non-specific clinical manifestations. Their sensitivity to chemotherapy and radiotherapy is limited and surgery remains the only curative treatment in symptomatic cases, however observational waiting could consist the most appropriate management in selected asymptomatic patients, moreover it could avoid unnecessary morbidity from surgery or radiotherapy, which makes the management of this condition a multidisciplinary decision and should be adapted to fit the patients individually. We report a case of a retroperitoneal desmoid tumor in a 31-year-old woman with a history of familial adenomatous polyposis, through which we will discuss this extremely rare neoplastic entity.