A Case of Solitary Fibrous Tumor of the Small Intestine Treated with Laparoscopic Surgery

Abstract

A 62-year-old woman was found to have a 40mm tumor in the small intestine by abdominal contrast-enhanced CT scan during the evaluation of obstructive rectal cancer (cT4aN1bM0, Stage IIIB). We placed a stent in the rectum, but it failed to maintain patency, so we performed laparoscopic ileostomy. At the same time, we performed partial resection of the small intestine to remove the small bowel tumor. Histopathology revealed tumor cells with oval-shaped, enlarged nuclei forming pseudovascular spaces, accompanied by multinucleated giant cells scattered in the stroma. Immunohistochemical staining showed positivity for CD34, bcl-2, and STAT6, and a genetic panel testing identified a NAB2exon6-STAT6exon17 fusion gene, leading to a diagnosis of a solitary fibrous tumor (SFT) of the small intestine.

Small bowel SFTs are rare, and no prior reports exist of laparoscopic resection for such cases. However, for small tumors like in this case, laparoscopic resection can be a minimally invasive and effective option. This case is significant as it represents a rare example of a tumor with atypical histopathological features undergoing genetic testing, providing valuable insights into its genetic characteristics.