Coexistence of gastrointestinal stromal tumor and leiomyosarcoma of the stomach presenting as a collision tumor: A case report and review of literature. Issue 5 (25th March 2018)

• Record Type: Journal Article
• Authors: Kitagawa, Hiroki; Kaneko, Mayumi; Kano, Mikihiro; Ibuki, Yuta; Amatya, Vishwa Jeet; Takeshima, Yukio; Hirabayashi, Naoki; Hirota, Seiichi
• Is Part Of: Pathology international. Volume 68:Issue 5(2018)
• Page Start: 313
• Page End: 317
• Publication Date: 2018-03-25
• Subjects: collision tumor -- gastrointestinal stromal tumor -- leiomyosarcoma -- stomach; Pathology -- Periodicals; 616.07
• DOI: 10.1111/pin.12662
• Languages: English
• ISSNs: 1320-5463

Abstract

Abstract : Collision tumor of the stomach is rare. We report a rare case of a gastric collision tumor consisting of gastrointestinal stromal tumors (GISTs) and leiomyosarcoma (LMS). Computed tomography scan revealed a 15 cm sized mass in the posterior wall of the body of the stomach. Gross examination of the wedge resection specimen showed the tumor located in the muscularis propria with extramural protrusion into the peritoneal cavity and the gastric cavity with geographic necrosis, hemorrhage, and mucosal ulceration. Histologically, the majority of the tumor consisted of the GIST component and the minor area in the submucosal region consisted of the LMS component. The tumor showed an abrupt transition between GIST and LMS by histologically and immunohistochemically, suggesting a collision tumor. Furthermore, the GIST components exhibited a c‐ kit exon 11 mutation. On the other hand, LMS component exhibited neither c‐ kit nor platelet‐derived growth factor receptor‐alpha (PDGFRA) mutation. Here we describe a case of the collision tumor consisting of GIST and LMS and its literature review.