title: Gastrointestinal stromal tumor in the duodenum exhibiting hemangiopericytoma-like histological pattern.
abstract: Reported herein is a gastrointestinal stromal tumor (GIST) that exhibited a hemangiopericytoma (HPC)-like histological pattern. Such a morphological variant of GIST has not been described previously. A 57-year-old woman presented with bloody stools. On upper digestive tract endoscopy a submucosal tumor of diameter 2 cm was detected at the duodenal bulb, and enucleated. Grossly, the tumor was well-circumscribed, grayish to whitish, and solid, and its central portion was ulcerated. Histology indicated round to fusiform tumor cells that had proliferated around branching vessels that had a staghorn configuration. Immunohistochemistry showed that the tumor cells were diffusely positive for vimentin and KIT; partially positive for CD34 and muscle actin; and negative for alpha-smooth muscle actin. On mutation analysis a 42 bp deletion was found from codons 560 to 573 of exon 11 of the KIT gene, which is a mutational hot spot of GIST. In diagnosis of gastrointestinal tract tumors with an HPC-like histological pattern, pathologists should consider the possibility of GIST.
authors.affiliation: Department of Pathology, Teikyo University School of Medicine, Kaga, Itabashi-ku, Tokyo, Japan. ytakaha-tky@umin.ac.jp
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Shimizu
authors.forename: Shinji
authors.initials: S
authors.lastname: Sakurai
authors.forename: Arisa
authors.initials: A
authors.lastname: Kumagai
authors.forename: Shigeo
authors.initials: S
authors.lastname: Mori
authors.forename: Toshio
authors.initials: T
authors.lastname: Fukusato
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis; D004379:Duodenal Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D017353:Gene Deletion; D006393:Hemangiopericytoma / Q000473:pathology*; D006801:Humans; D008875:Middle Aged; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis / Q000235:genetics; D014746:Vimentin / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D014746:Vimentin; D019009:Proto-Oncogene Proteins c-kit