Objective: Desmoid tumours are benign growths of fibro-aponeurotic tissue that are rare in the general population but pose problems in patients with familial adenomatous polyposis (FAP). Many reports of patients with desmoid tumours are unhelpful because of small numbers, inclusion of patients with and without FAP, failure to separate tumours in different sites and use of a wide variety of treatment combinations. The purpose of this study was to avoid some of these deficiencies by reviewing the clinical course of a large number of patients, all of whom have intra-abdominal desmoids and FAP.
Patients and methods: The medical records of patients with intra-abdominal desmoids treated at this institution were identified through the database in the David G. Jagelman FAP Registry and reviewed. Only patients who received all or part of their treatment at the Cleveland Clinic were included. Protocols for desmoid follow up call for periodic measurement of the dimensions of the tumour, either by clinical examination or on computed tomography (CT) scan. The interval between examinations ranges from 3 months to 2 years, depending on the presence of symptoms and the rate at which the tumour is growing. A change in greatest diameter of >50% is deemed significant growth or regression.
Results: Seventy patients with intra-abdominal desmoid tumours in the setting of FAP were identified. Mean age at desmoid diagnosis was 31 years; there were 24 men and 46 women. A family history of desmoids was present in 53% of families known to have FAP. Abdominal wall tumours were also present in 18 patients. Most desmoids presented after surgery (53/70) and multiple tumours were found in 24 patients. The commonest presentation of desmoid tumours was as an abdominal mass. One third of patients had no symptoms at presentation. Treatment included surgery (32), medicine (41) chemotherapy (10) and radiation (4). Eleven patients received no treatment. At the time of review 12 patients were dead (11 from desmoids), 15 were symptomatic and 41 asymptomatic. In seven cases the desmoid disappeared, two spontaneously, two after excision, and three after chemotherapy. Thirty-four patients were being treated at the time of review, 29 with sulindac.
Conclusion: The outcome in these cases shows that most intra-abdominal desmoid tumours in FAP are indolent mass lesions that may vary a little in size and do not cause serious harm to the patient. Medical treatments are usually ineffective; surgery is at best unwise and at worst the cause of disastrous complications. A small proportion of desmoids grow rapidly and usually lead to the patient's death. For these patients, anti-sarcoma type chemotherapy is the only hope.