Malignant stromal tumors of the small bowel: report of 9 cases

Purpose. Analysis of imaging features of malignant stromal tumors of the small bowel and review of literature. Material and Methods. 9 cases of malignant stromal tumor of the small bowel with histological proof were imaged at US (8 cases), small bowel series (9 cases) and CT scan (3 cases). Results. There were 6 cases of ieiomyosarcoma and 3 cases of malignant schwannoma. Tumors involved the jejunum in 3 patients, the ileum in 4 patients, and the duodenum in 2 patients. The main clinical presentation was an abdominal mass (8 cases), which appeared heterogeneous and hypoechoic with eccentric lumen at US confirming its G1 origin (7 cases). Small bowel series showed a bulky cavitary mass opacified via a thin fistula (7 cases), an ileo-ileal intussusception (1 case) and enlarged duodenal lumen (1 case). CT performed in 3 cases showed an intraperitoneal mass with soft-tissue density. A communication with the GI tract was noted in 1 case, and in another case, it showed an intestinal intussusception. US guided biopsy performed in 3 cases provided diagnosis in 2 cases (malignant schwannoma, leiomyosarcoma). Tumor growth was exophytic in 8 cases and dumbbell-shaped in 1 case. Conclusion. The imaging features of malignant stromal tumors of the small bowel are similar. It varies with the type of tumor growth and its size. The diagnosis may be suggested based on imaging features.