Progression of infiltrative desmoid tumor following total colectomy in familial adenomatous polyposis
Presentation
History of familial polyposis and total colectomy.
Patient Data
Baseline (5yr post colectomy)
Total colectomy with ileoanal anastomosis.
Strandy soft tissue infiltration of the mesentery.
Year 5: growth
More extensive soft tissue infiltration of the mesentery with mesenteric venous collaterals forming.
Year 7: more extensive growth
Much more dramatic grown of infiltrative soft tissue in the mesentery, which is displacing and potentially invading into small bowel loops. There is multifocal narrowing of the mesenteric veins.
Year 8: complicated by fistula
Growth of mesenteric masses with infiltrative appearance displacing and invading into small bowel loops. Obstruction of the right ureter. New enhancing air/fluid collection in the mesentery. Multifocal mesenteric venous narrowing.
Year 9: fistulae & obstruction
Right percutaneous nephrostomy tube. End stage disease with enlargement of mesenteric masses, multiple abdominal collections with drainage catheters, and small bowel obstruction.
Case Discussion
Progressive and tragic case of infiltrative mesenteric desmoid tumor which occurred 5 years following prophylactic total colectomy in a patient with familial adenomatous polyposis (FAP). These patients are at particularly high risk for developing desmoid tumors (especially following surgery), and they are an important cause of morbidity and mortality.
Imaging takeaways:
- while many desmoid tumors are round and well-circumscribed, they can also be infiltrative (or mixed well-defined and infiltrative);
- the degree of soft tissue infiltration should not be mistaken for sclerosis mesenteritis which is typically more central and associated with pseudocapsule/fat ring (early mesenteric panniculitis) or retraction and calcifications (later retractile mesenteritis)
- while peritoneal lymphoma or mesothelioma can overlap with this appearance, the lack of adenopathy or peritoneal/serosal implants (and the patient history) can rule these out
- have a high suspicion for abdominal tumors or soft tissue when reviewing imaging for FAP patients; while most commonly intra-abdominal, they can also occur at port sites, body wall, and incisions
- notice the progressive narrowing of mesenteric vasculature, consistent with an infiltrative fibrosing process
- tragically, at the end stage this eroded through the bowel wall and resulted in desmoid-enteric fistula and small bowel obstruction