title: Gut wall replacing type of gastrointestinal stromal tumor presenting as a perforation of the ileal diverticulum.
abstract: Gastrointestinal stromal tumors (GISTs) usually form a well-circumscribed mass. Very rarely, however, sporadic GISTs show gut-wall replacing growth, similar to the diffuse hyperplasia of interstitial cells of Cajal (ICC) observed in patients with neurofibromatosis type 1 (NF1) and hereditary GIST. Here we describe a patient with ileal perforation caused by this unusual type of GIST. An 82-year-old man was admitted to the emergency department with sudden abdominal pain. Following a provisional diagnosis of perforation of Meckel's diverticulum, he underwent segmental resection of the small intestine. Macroscopic examination revealed a diverticulum-like structure 2.5cm in size near the site of mesenteric attachment of the ileum. Histological examination showed diffuse and nodular proliferation of spindle cells positive for c-KIT and CD34 that had replaced the muscularis propria of the small intestine. Mutational analyses of the lesions revealed monoclonality of proliferating cells with a somatic mutation in c-kit exon 11 (p.Leu576Pro). Gut-wall replacing type of GIST should be recognized as a specific type of GIST causing diverticulum-like structures of the gastrointestinal tract.
authors: Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Masako
authors: M
authors: Ikemura
authors: Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Akiko
authors: A
authors: Kunita
authors: Department of Gastrointestinal Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Yoshiyuki
authors: Y
authors: Miwa
authors: Department of Gastrointestinal Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Keiichi
authors: K
authors: Jimbo
authors: Department of Gastrointestinal Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Kazuhiko
authors: K
authors: Mori
authors: Department of Gastrointestinal Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Yasuyuki
authors: Y
authors: Seto
authors: Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: mfukayama-tky@umin.ac.jp.
authors: Masashi
authors: M
authors: Fukayama
mesh_terms: D000369:Aged, 80 and over; D004252:DNA Mutational Analysis; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics / Q000473:pathology*; D006801:Humans; D007416:Intestinal Perforation / Q000209:etiology*; D008297:Male; D008467:Meckel Diverticulum / Q000473:pathology*; D009154:Mutation; D016133:Polymerase Chain Reaction; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics
chemical_list: D019009:Proto-Oncogene Proteins c-kit
keywords: Deverticulum; Gastrointestinal stromal tumor; Meckel's deverticulum; Perforation