Case Report
Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Dec 21, 2008; 14(47): 7256-7259
Published online Dec 21, 2008. doi: 10.3748/wjg.14.7256
Primary multiple extragastrointestinal stromal tumors of the omentum with different mutations of c-kit gene
Tadashi Terada
Tadashi Terada, Department of Pathology, Shizuoka Municipal Shimizu Hospital, Miyakami 1231, Shimizu-Ku, 424-8636, Shizuoka, Japan
Author contributions: Terada T contributed all to this paper.
Correspondence to: Tadashi Terada, MD, PhD, Department of Pathology, Shizuoka Municipal Shimizu Hospital, Miyakami 1231, Shimizu-Ku, 424-8636, Shizuoka, Japan. piyo0111jp@yahoo.co.jp
Telephone: +81-543-36-1111 Fax: +81-543-36-1173
Received: April 4, 2008
Revised: November 12, 2008
Accepted: November 19, 2008
Published online: December 21, 2008
Abstract

The author reports a very rare case of sporadic primary multiple extragastrointestinal stromal tumors (EGISTs) of the omentum associated with different mutations of the exon 11 of the c-kit gene in a 75-year-old man with gastric cancer. During an operation for the cancer, two solid tumors (10 mm and 8 mm) were found in the omentum. Both tumors consisted of cellular spindle cells. Mitotic figures were two and three per 50 high power fields. The tumor cells were positive for KIT, CD34 and vimentin, but negative for desmin, S100 protein, α-smooth muscle actin and p53 protein. Ki67 labeling was 2% and 3%. The larger EGIST showed a deletion of codons 552-558 of exon 11 of the c-kit gene, while the smaller EGIST had a point mutation at codon 559 (GTT←GAT) in exon 11 of the c-kit gene. Exons 9, 13, and 17 of the c-kit gene, and exons 12 and 18 of the platelet derived growth factor receptor α genes showed no mutations. The case shows that sporadic multiple EGISTs can occur in the omentum.

Keywords: Omentum; Extragastrointestinal stromal tumors; c-kit; Platelet derived growth factor receptor; CD34