BACKGROUND: Intra-abdominal fibromatosis is a benign rare tumor of fibrous origin with a significant potential for local invasion and no ability to metastasize, but it can recur. The etiology of desmoid tumors is unknown. It is often associated with conditions such as familial adenomatous polyposis and Gardner syndrome.

CASE REPORT: We report the case of a 69-year-old man who presented to our hospital with an acute pulmonary embolism. The patient had a past history of colic surgery for a polyp with a high-grade dysplasia. Pulmonary angiography showed partial occlusion of the right superior lobe artery and partial occlusion of the middle lobe artery. The patient was given thrombolytic therapy. Abdominal computerized tomography revealed a mesenterial giant mass with compression of the inferior vena cava (IVC). A biopsy of the mass, confirming aggressive fibromatosis. A laparotomy was performed, which revealed a massive growth occupying the abdomen and attached to the previous ileocolic anastomosis. One day after surgery, his condition deteriorated.

CONCLUSIONS: This report underlines the potential of imaging investigations of abdomen and vena cava if pulmonary embolism is suspected, especially when there is no evidence of peripheral venous thrombosis or other predisposing factors. Unfortunately, data on the surgical management of desmoid tumor is scarce. Therefore, the standard of treatment is a surgical resection for resectable tumors.

Keywords: Angiography, Biopsy, Constriction, Pathologic - diagnosis, Diagnosis, Differential, Fibrinolytic Agents - therapeutic use, Fibromatosis, Aggressive - surgery, Laparotomy, Mesentery, Peritoneal Neoplasms - surgery, Pulmonary Embolism - etiology, Thrombolytic Therapy, Tomography, X-Ray Computed, Vena Cava, Inferior