ISPUB.COM The Internet Journal of Surgery Volume 10 Number 1 1 of 4 Extragastrointestinal Stromal Tumor: A Report Of A Rare Case S Sahu, P Srivastava, N Chauhan, S Kishore, D Bahl, P Sachan Citation S Sahu, P Srivastava, N Chauhan, S Kishore, D Bahl, P Sachan. Extragastrointestinal Stromal Tumor: A Report Of A Rare Case. The Internet Journal of Surgery. 2006 Volume 10 Number 1. Abstract Extragastrointestinal stromal tumors (EGIST) are mesenchymal tumors that occur outside the gastrointestinal tract and show histological appearance similar to the gastrointestinal stromal tumor and a positive c-kit expression. Only a few cases of EGISTs are reported. We report a rare case of extragastrointestinal stromal tumor of omentum, which was treated by surgical excision. INTRODUCTION Mesenchymal tumors arising from the wall of the gastrointestinal tract have attracted a great deal of attention over the years. In the literature, different nomenclatures have been given to these tumors in the past. Leiomyoma, leiomyoblastoma and leiomyosarcoma were some of the terms used, as they were believed to originate from the smooth muscle layers of the gastrointestinal wall. 1 The term Gastrointestinal stromal tumor (GIST) was first proposed by Mazur and Clark in 1983 to describe those gastrointestinal non-epithelial neoplasms that lacked the immunohistochemical features of Schwann cells and did not have the ultra structural characteristics of smooth muscle cells. 2 Tumors previously described as gastrointestinal autonomic nerve tumor (GANT) are now regarded as a variant of GIST. 3 CASE REPORT A 22-year old female was admitted with history of severe pain in the lower abdomen since five days. At the time of admission her vital parameters were within normal limits. Examination of abdomen revealed diffuse tenderness with guarding in the lower half of the abdomen. Investigations revealed: Hemoglobin 11.4gm/dl, Total leukocyte count 19390/cu.mm, Differential leukocyte count: neutrophils 82%, lymphocytes 12%, eosinophils 2% and lymphocytes 4%. Renal function and liver function tests were within normal limits. Imaging study in the form of ultrasonography of abdomen revealed a large right adnexal mass with predominantly multiple cystic areas of varying sizes, showing internal echoes with few solid areas [FIG-1]. Figure 1 Figure 1: Ultrasonography of the abdomen showing a large adnexal mass with predominance of multiple cystic areas of varying sizes with internal echoes and few solid areas. Exploratory laparotomy was planned which revealed a large intraperitoneal mass composed of omentum and loops of ileum with few areas of cystic and hemorrhagic degenerations and a perforation in the involved loop of ileum. Resection of the involved omentum and ileum with primary end-to-end ileoileal anastomosis was done. Postoperatively the patient had an uneventful recovery. Histopathology of the specimen showed a nodular and circumscribed smooth muscle tumor in the omentum showing whorling at few places with the smooth muscle fibres arranged in parallel bundles. [FIG-2] [FIG-3]