Background: Desmoid tumours are one of the most important and intriguing extracolonic manifestations of familial adenomatous polyposis (FAP). They have been studied only in small numbers of patients.
Methods: Patients with FAP who also had desmoid tumour were identified from a polyposis registry database and their hospital notes were reviewed.
Results: There were 166 desmoids in 88 patients (median age 32 (interquartile range 22-38) years; 51 (58 per cent) female); 83 tumours (50 per cent) were within the abdomen and 80 (48 per cent) were in the abdominal wall. All but 16 individuals (18 per cent) had already undergone abdominal surgery, which was significantly more recent in women (P = 0.01, Mann-Whitney U test). Intra-abdominal desmoids caused small bowel and ureteric obstruction and resulted in ten deaths; survival was significantly poorer than in patients with abdominal wall desmoid alone (chi2 = 3. 93, 1 d.f., P = 0.047, log rank test), and eight of 22 patients who underwent resection of intra-abdominal desmoid died in the perioperative period.
Conclusion: Abdominal wall desmoids caused no deaths or significant morbidity; although recurrence was common after excision, the treatment was safe. Intra-abdominal desmoids can cause serious complications and treatment is often unsuccessful; in particular, surgery for desmoids at this site is hazardous.