Gastrointestinal Stromal Tumor with Extensive Lymphatic Metastasis: A Case Report
A 53-year-old male cadaver was donated to our laboratory. He was 175 cm tall and weighed 80 kg. The cause of death was acute myocardial infarction. There was no evidence of trauma or surgery. During an autopsy, the authors observed morphological features and distribution of the tumors and took photographs. The histological samples were obtained and analysed by hematoxylin-eosin stain and immunohistochemistry and then consulted with pathologist on the microscopic findings of the tumors.\nAfter the opening of the anterior abdominal wall and peritoneum, a large number of round and various-sized tumors (0.5~2.4 cm in diameter) were exposed on the greater omentum (). The superior part of the greater omentum was stuck in the right iliac fossa and adhered to adjacent peritoneal surfaces. The authors examined the intestinal loop following the removal of the greater omentum, and then the first primary mass was detected on the ileum at 90 cm proximal to the ileocecal junction. The mass was 6.1×3.4×4.0 cm sized. It was firm and adhered to adjacent parietal peritoneum and the greater omentum. A cutting plane of the mass was bright brown coloured and the cavity of the central necrosis was open to the lumen of the intestine (). The second primary mass was detected at the middle of the small intestinal loop and 3.7×4.2×3.2 cm sized (). It was adhered to adjacent small bowel and its cutting plane was bright brown coloured. The small foci of the central necrosis and a pattern of swirl were also observed on cutting planes. Moreover, a lot of mesenteric and iliac lymph nodes were enlarged.\nThe tumor mass lied within the tunica muscularis of the intestinal wall and there was no evidence of mucosal invasion. The tumor cells were spindle-shaped and densely packed in swirling pattern. The cytoplasm of the cells were eosinophilic and the nucleus did not show distinct mitotic figure. Lymphatic spread was confirmed by identification of the subcapsular lymphatic sinus within the pathologic samples obtained from the greater omentum, mesentery, and posterior abdominal wall (). The CD117 antigen was negative and the CD34 was partially positive in immunohistochemical assay (). The desmin and the S-100 protein were not detected. Consequently, the authors diagnosed this tumor as the GIST with lymph node metastasis on the basis of the diagnostic guide of Hirota and Isozaki.