title: Gastrointestinal stromal tumor presenting with prominent calcification.
abstract: We present a rare case of a gastrointestinal stromal tumor (GIST) in the stomach with prominent calcification at presentation. A 61-year-old woman visited our hospital because of epigastric discomfort. A spherical calcified lesion with a diameter of about 30 mm was incidentally shown in the left upper quadrant on an abdominal X-ray. Computed tomography demonstrated that the tumor was growing from the upper gastric body, with calcification in the peripheral ring area. A laparoscopic partial gastrectomy was performed, and the resected specimen revealed a well-circumscribed tumor with exophytic growth from the gastric muscularis propria. Microscopic examination revealed spindle-shaped tumor cells with calcification and hemorrhage. Additionally, positive immunoreactivity of the tumor to KIT and CD34 and a low mitotic index resulted in the diagnosis of very low risk GIST. There are a few case reports of heavily calcified GIST, although solitary or punctate calcification of primary GIST has been reported in several case series. Dystrophic calcification of necrotic or degenerative tissue is the supposed cause of primary calcified GISTs. In contrast, appearance of calcification after administration of imatinib mesylate, which may be one indicator of disease response, is possibly caused by a different mechanism.
authors.affiliation: Division of Gastroenterology and Hepatology, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Izawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sawada
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Abiko
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kumon
authors.forename: Mami
authors.initials: M
authors.lastname: Hirakawa
authors.forename: Mika
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Obinata
authors.forename: Masahito
authors.initials: M
authors.lastname: Nomoto
authors.forename: Tadateru
authors.initials: T
authors.lastname: Maehata
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Yamauchi
authors.forename: Takefumi
authors.initials: T
authors.lastname: Kouro
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kitajima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yasuda
authors.forename: Keiichi
authors.initials: K
authors.lastname: Tanaka
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tanaka
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hoshikawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takagi
authors.forename: Fumio
authors.initials: F
authors.lastname: Itoh
mesh_terms: D002114:Calcinosis / Q000209:etiology*; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000150:complications / Q000175:diagnosis*; D046152:Gastrointestinal Stromal Tumors / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged
keywords: Calcification; Computed tomography; Gastrointestinal stromal tumor; Imatinib mesylate; Stomach