title: Extragastrointestinal stromal tumor originating from the vulva.
abstract: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. They have gain-of-function mutations of the c-kit receptor tyrosine kinase gene and have been suggested to originate from the interstitial cells of Cajal. A small percentage of GISTs form extragastrointestinal masses. We report a rare case of a GIST originating from the vulva. A 55-year-old woman presented with a vulvar tumor. The tumor was initially diagnosed as a leiomyosarcoma following the first resection. Following a second recurrence the patient was administered chemotherapy. A third recurrence occurred and the patient underwent a third resection. Histology revealed that a bundle of fibrous tumor cells had invaded the connected tissue and muscular coat, and some spindle-shaped and blunt-ended nuclei were detected. Furthermore, immunohistochemical evaluation revealed that the tumor cells exhibited strong and diffuse staining for c-kit and CD34. The recurrent tumor was diagnosed as a GIST and a reevaluation of the original specimens also revealed a GIST. The patient was treated with imatinib, and is currently healthy with no evidence of recurrence at 20 months after the last surgery.
authors.affiliation: Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, Osaka 545-8585, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fukuda
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sumi
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nakano
authors.forename: Masanari
authors.initials: M
authors.lastname: Morishita
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nobeyama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshida
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Yasui
authors.forename: Ken-Ichi
authors.initials: KI
authors.lastname: Honda
authors.forename: Osamu
authors.initials: O
authors.lastname: Ishiko