title: Extra-gastrointestinal stromal tumor of the pelvic cavity: case report.
abstract: Extra-gastrointestinal stromal tumors (E-GISTs) not associated with the alimentary tract in the pelvic cavity are extremely rare. We treated a 49-year-old Japanese man with such an E-GIST in the pelvic cavity who underwent an intrapelvic tumorectomy with a total prostatectomy and partial rectum resection. Gross examination of the specimen revealed an 8.1 × 5 × 4 cm white-grayish mass. Histological findings showed uniform spindle cells with scant atypia that formed interlacing bundles or whorl patterns. These neoplastic cells did not invade adjacent organs, including the gut. Immunohistochemical findings revealed that the neoplastic cells were positive for c-kit, CD34, and vimentin. Molecular analysis showed a c-kit mutation at exon 9 with duplication of Ala and Tyr. Our diagnosis was E-GIST, which belongs to the intermediate group of GIST. Following the operation, we administered imatinib mesylate for 6 months. After stopping for 5 months, it was administered again for local recurrence. We are planning our future strategy for this case including surgical resection as necessary.
authors.affiliation: Department of Pathology, Steel Memorial Hirohata Hospital, Hyogo, Japan. hirano_hiroshi@hospital.sanda.hyogo.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hirano
authors.forename: Toshimi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yoshimura
authors.forename: Masato
authors.initials: M
authors.lastname: Fukuoka
authors.forename: Noriko
authors.initials: N
authors.lastname: Ohmura
authors.forename: Yuusuke
authors.initials: Y
authors.lastname: Nishizawa
authors.forename: Shiro
authors.initials: S
authors.lastname: Tachibana
authors.forename: Seiichi
authors.initials: S
authors.lastname: Hirota
authors.forename: Masataka
authors.initials: M
authors.lastname: Zozumi
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishigami
mesh_terms: D018952:Antigens, CD34 / Q000235:genetics / Q000378:metabolism; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001549:Benzamides; D005091:Exons / Q000235:genetics; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D006801:Humans; D000068877:Imatinib Mesylate; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010388:Pelvis / Q000473:pathology / Q000601:surgery; D010879:Piperazines / Q000627:therapeutic use; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D011743:Pyrimidines / Q000627:therapeutic use; D014746:Vimentin / Q000235:genetics / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D014746:Vimentin; D000068877:Imatinib Mesylate; D019009:Proto-Oncogene Proteins c-kit