A Case of Malignant Duodenal Stromal Tumor

Jeon, Byung Cheol; Jeong, Min Young; Suh, Jeong Ill; Yang, Chang Heon; Kim, Seong Cheol; Lee, Chang Woo; Jeong, Byung Wook; Kim, Jung Ran; Bae, Han Ik

Abstract

Malignant stromal tumors of the small intestinal tract are uncommon and their clinical behavior is notoriously unpredictable. Gastrointestinal stromal tumors are spindle cell tumors occurring mainly in adults with 5-year survivals of 50-56% and 10-year survivals of 35-43%. Factors playing a prominent role in predicting their biological behavior are tumor site, size, and degree of mitotic activity. We report a case of malignant stromal tumor of the duodenum presenting as melena in a thirty year old man. The endoscopy showed a polypoid mass with central deep ulceration at the second portion of the duodenum. A subserosal nodular portion showed high mitotic area (4 per one HPF). Microscopically, it was composed of mainly bland spindle cells. However, a subserosal round nodule showed numerous mitoses up to 5-6 mitoses per one high power field. A monoclonal antibody to proliferating cell nuclear antigen (PCNA), PC1O, is a marker for the proliferative activity of tumor cells. The nodular cellular area showed a high PCNA labelling index and had a correlation with high mitotic count. This finding may reflect evidence of malignant clonal evolution in a benign stromal tumor.