title: Unusual sonographic appearance of a gastrointestinal stromal tumor presenting as a large multilocular cystic mass.
abstract: Cystic change is uncommon in gastrointestinal stromal tumor, (GISTs). This report describes 1 case in which a GIST presented as a large multilocular cystic mass. Sonography of the abdomen showed a huge cystic lesion with multiple septa in the left upper quadrant of the abdomen, compressing the left lobe of the liver. Esophagogastroscopy showed only a small submucosal tumor at the anterior wall of the mid portion of the gastric body. Endoscopic sonography revealed a hypoechoic mass, measuring 0.9 x 0.7 cm, arising from the fourth layer of the anterior wall of the mid portion of the gastric body. A huge cystic tumor, containing multiple septa and continuous with the small submucosal lesion, was found. Doppler signals were detected within the septa. Laparotomy revealed a huge exophytic cystic tumor arising from the stomach. Immunohistochemical analysis confirmed that the lesion was a GIST by detecting expression of the c-kit and CD34 proteins. GIST that has undergone cystic change must be differentiated from other cystic lesions to guide the treatment approach. Imatinib mesylate is a new therapeutic alternative for patients who have advanced GIST, but surgery remains the therapy of choice for resectable disease.
authors.affiliation: Department of Internal Medicine, College of Medicine, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei 100, Taiwan.
authors.forename: Chi-Yang
authors.initials: CY
authors.lastname: Chang
authors.forename: Hsiu-Po
authors.initials: HP
authors.lastname: Wang
authors.forename: Tasui-Lien
authors.initials: TL
authors.lastname: Mao
authors.forename: Rey-Heng
authors.initials: RH
authors.lastname: Hu
authors.forename: Pei-Ming
authors.initials: PM
authors.lastname: Yang
authors.forename: Ming-Yang
authors.initials: MY
authors.lastname: Lai
authors.forename: Jaw-Town
authors.initials: JT
authors.lastname: Lin
mesh_terms: D003560:Cysts / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D017154:Stromal Cells / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography