A lethal mesenteric gastrointestinal stromal tumor: a case report and review of the literature.

Gastrointestinal stromal tumors (GISTs) arising from the mesentery are very rare. Here, we report a 53-year old man with a huge lobulated cystic-solid tumor in the left lower quadrant of the abdomen, which had been proved clinically and radiographically. Surgical resection showed that the large mass was noted at the mesentery of small intestine. Grossly, the largest diameter of the mass were measured up to 23 cm, and poorly circumscribed. Histological observation demonstrated it as a malignant GIST with positive CD117 (c-kit) staining. Mitotic figures were frequently observed up to 110 per 50 high power fields. Soon after the surgery, the patient experienced local recurrence with quick growth. The patient received targeted therapy (imatinib mesylate) but had no ideal effect. The patient died nine months after the operation because of rapid disease progression.