Malignant appendiceal GIST: case report and review of the literature.

INTRODUCTION: Gastro-intestinal stromal tumors (GISTs) of the appendix are a rare entity. To date, only a handful has been described in the literature, all of which have been of the benign type. CASE REPORT: We present the first reported case of a malignant appendiceal GIST. The tumor was discovered when the patient presented with a peri-appendiceal abscess which appeared suspicious on CT. The abscess was drained and managed medically. The patient responded to antibiotic treatment but subsequent CT and biopsy confirmed the diagnosis of appendiceal GIST, and the patient was started on treatment with imatinab mesylate. DISCUSSION: One week after initiation of therapy, the patient returned with frank peritonitis necessitating surgery. Abdominal exploration revealed an appendiceal GIST locally invading and perforating adjacent bowel. We describe the complex presentation and course of the case as well as a literature review of the appendiceal GISTs and the current approach to treatment.