Desmoid tumors: clinical features and outcome of an unpredictable and challenging manifestation of familial adenomatous polyposis.

Background/Aims Desmoid tumors (DTs) are rare, locally invasive neoplasms that may affect 10-25% of familial adenomatous polyposis (FAP) patients. Our aim was to evaluate incidence and clinical presentation among our patients, the potential impact on FAP outcome and to discuss treatment. Materials and methods Charts from 133 FAP (1977-2013) were reviewed. Patients with DTs were separated to retrieve demographic, clinical and management data. Follow-up was focused on disease evolution causing complications or death. Results 19 (14.3%) DTs were diagnosed, either after previous trauma (16) or during FAP surgery (3). This group comprised 8 men (42.1%) and 11 women (57.9%) with an average age of 32.9 years. Intervals from surgical trauma to DTs ranged from 7 to 60 months. ECMs were detected in 12 (63.1%) patients. DTs were located in the abdominal wall (8), abdominal cavity (8), abdominal wall and cavity (2) and left arm (1). Five patients (26.3%) referred family history of DTs. Patients presented severe complications such as small bowel obstruction (4) and hydronephrosis (2), being directly responsible for death in three patients. Conclusions (1) DTs developed in 14.3% of FAP, mostly after surgical trauma; (2) 30% caused severe morbidity; (3) identification of clinical risk factors may help surgeons to develop screening and therapeutic decisions.