Abstract
A 77-year-old man was transferred to our hospital under the suspition of the invagination caused by a small bowel tumor. Abdominal CT revealed a partially enhancing jejunal tumor, which was the front of the invagination. An upper gastrointestinal series showed a well-designed and round filling defect in the upper jejunum, and enteroscopy revealed a submucosal tumor, 5cm in diameter, which showed good mobility, with a Delle at the top of the tumor. We finally performed laparotomy because of repeated ileus symptoms. The jejunum was invaginated by the tumor, and we performed partial resection of the jejunum after reduction of the invagination. The resected specimen showed a peduncular tumor, 3.5×2.5cm in size, and its cut surface was uniformly whitish and solid. Histopathological examination showed infiltration of the submucosa by inflammatory cells, predominantly myofibroblastic cells. Immunohistochemical analysis of the tumor showed positive staining for vimentin, and negative staining for SMA, CD34, desmin, and S-100 protein. Based on the findings, a final diagnosis of inflammatory myofibroblastic tumor（IMT）was made. Primary gastrointestinal tract IMT is a relatively rare disease, therefore, this case is reported here together with some bibliographical comments.
