A case of gastrointestinal stromal tumor of the duodenum in a young male

We reported a case of gastrointestinal stromal tumor (GIST) of duodenum in a young male. A 32-year-old male was admitted to our hospital because of right upper abdominal tumor. Abdominal CT revealed a tumor (10 cm in diameter) with necrosis developed extramurally from the second portion of the duodenum. Endoscopic examination revealed a tumor with easy bleeding ulcer of the second portion of the duodenum. Histopathological examination of biopsy specimens suggested that this tumor was a stroml tumor. Angiography revealed that this tumor was feeding with PSPD and ASPD. We performed pancreatoduodenectomy. Histopathologically, this tumor was composed of spindle cells arranged in interlacing-bundled pattern. Immunohistochemically, tumor cells were positive for CD34 and new myogenic markers (caldesmon and calponin) , but were negative for clasical myogenic markers (SMA, desmin) and Schwann cell markers (S-100 protein and Leu7) . Therefore, it was diagnosed as a duodenal stromal tumor with cajal cell and myogenic origin. We will need to study large number of patients to clarify diagnosis and malignant potential of GIST.