title: Gastrointestinal stromal tumors: CT and MRI findings.
abstract: The objective of this study was to report the CT and MRI appearances of primary and metastatic gastrointestinal stromal tumor (GIST). The clinical and imaging findings of 31 patients with histological and immunohistochemical diagnosis of GIST were reviewed. The CT and MRI findings were assessed independently for size, location, enhancement characteristics, and pattern of metastatic disease. The tumors were of enteric (n=13), gastric (n=12), duodenal (n=2), and rectal (n=3) origin. In one case the primary site was the mesentery, without involvement of bowel. Primary tumors were typically exophytic (79%), larger than 5 cm (84%), and inhomogeneously enhancing (84%). Central necrosis of all tumors (37%) and aneurysmal dilation of enteric tumors (33%) were less common. Metastases were most commonly to mesentery (26%) or liver (32%). Less common findings were ascites (7%) and omental caking (3%). Liver metastases were hypervascular in 92% of patients and rapidly became cystic following therapy with imatinib mesylate (Gleevec; Novartis, East Hanover, NJ, USA). Lung metastases, bowel obstruction, vascular invasion, and significant lymphadenopathy were not seen in any patient. GISTs have some specific CT findings which could help differentiate them from other gastrointestinal tumors. Liver metastases became cystic following therapy, mimicking simple cysts. MRI was better than single-phase CT for assessing liver metastases, while CT was more sensitive for mesenteric metastases.
authors.affiliation: Department of Radiology, Indiana University Medical Center, UH 0279, Indianapolis, 46202, USA. ksandras@iupui.edu
authors.forename: Kumaresan
authors.initials: K
authors.lastname: Sandrasegaran
authors.forename: Arumugam
authors.initials: A
authors.lastname: Rajesh
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Rushing
authors.forename: Jonas
authors.initials: J
authors.lastname: Rydberg
authors.forename: Fatih M
authors.initials: FM
authors.lastname: Akisik
authors.forename: John D
authors.initials: JD
authors.lastname: Henley
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001549:Benzamides; D004379:Duodenal Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000556:secondary; D006801:Humans; D007089:Image Enhancement; D000068877:Imatinib Mesylate; D007421:Intestine, Small / Q000000981:diagnostic imaging / Q000473:pathology; D008113:Liver Neoplasms / Q000556:secondary; D008279:Magnetic Resonance Imaging; D008297:Male; D008643:Mesentery / Q000473:pathology; D008875:Middle Aged; D010534:Peritoneal Neoplasms / Q000556:secondary; D010879:Piperazines / Q000627:therapeutic use; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011743:Pyrimidines / Q000627:therapeutic use; D011856:Radiographic Image Enhancement; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases