Système gastro-intestinal et digestif

Abstrait

Gastric Desmoid Tumor: An Infrequent Case of Intra-Abdominal Fibromatosis

Macias N, Abdel-lah O, Parreño FC, Blanco O, Bengoechea O, Martínez SC

Background and purpose: Desmoid tumors or aggressive fibromatosis are infrequent conditions, with a large clinical variability, and preferencial location on abdominal wall, extra-abdominal soft tissue, and mesentery. Histologically benign but locally aggressive, they have a marked tendency to recurrence. There are two known variants: sporadic and associated to familial adenomatous polyposis. Its etiology remains unknown, but it appears to be related to estrogenic estimulation, surgical aggression and mutations of the short arm of chromosome 5. Diagnosis is usually difficult, and must combine medical history, semiology and imaging, though only histological analysis of the specimen will provide a definitive diagnosis after surgical resection, which is potentially curative. Gastric location has not been reported so far. Case report: 37-year-old woman with recent delivery, presenting abdominal lump with non specific clinical semiology and rapid growth rate. After diagnostic tests, a hypervascular mass of about 15 centimeter of diameter, depending on gastric wall is found. She underwent an elective distal gastrectomy and Billroth I reconstruction. Histology confirms a mesenchymal desmoid gastric tumor. Discussion: The differential diagnosis for abdominal oligosymptomatic lumps which respect the mucosa of the gastrointestinal tract lead clinical suspicion to mesenchymal tumors such as sarcomas, desmoids, or GIST. Radiologic tests are useful to confirm resectability and detect complications. When facing unresectable disease, planning a biopsy and systemic treatment with chemotherapy and/or radical radiotherapy should be considered. Diagnosis is reached after histological and inmunohistochemical analysis of the specimen, which in case of a desmoid, will show negative expression to markers of sarcoma (actin, desmin, S100) or GIST (CD117, DOG1, PDGFRA), and positive staining with anti-beta-catenin. Conclusion: Desmoid tumors should be considered in the differential diagnosis of abdominal oligosymptomatic masses, specially in fertile women or if history of surgical trauma. Patients with desmoid tumors should undergo colonic polyposis screening, as well as patients with adenomatous polyposis and an abdominal lump should lead suspected diagnosis to the possibility of a desmoid tumor.