Gastrointestinal stromal tumor with diffuse mesenteric metastases.

Although malignant gastrointestinal stromal tumors (GISTs) sometimes show peritoneal dissemination, diffuse metastasis to only the mesentery is rare. We describe the unusual case of GIST in a 69-year-old woman who showed multiple nodules restricted only to the mesentery except the surface of the small and large bowel, omentum, and abdominal wall. These small nodules were similar to those seen in leiomyomatosis peritonealis disseminata. Histological and immunohistochemical findings were consistent with GIST. This case of GIST shows an apparently unique and rare spreading pattern.