[Imaging and pathological features of gastrointestinal stromal tumors].
OBJECTIVE
To investigate the imaging features and pathological manifestations of gastrointestinal stromal tumors (GISTs).


METHODS
The imaging characteristics and pathological manifestations of 26 surgically treated patients with histologically confirmed GISTs were retrospectively analyzed.


RESULTS
The tumors were found to originate from the small bowel (n=10), stomach (n=8), colon (n=6), mesentery (n=1) and omentum (n=1). The imaging and pathological features of GISTs were (1) most of GISTs were well-defined and exophytic (n=19, 73.1% ), which usually compressed the adjacent tissues but no invasion. The tumor diameter ranged from 5.1 to 23.5 cm with a mean diameter of 11.6 +/- 5.9 cm, (2)most tumors had an inhomogenous density or signal intensity due to necrosis(n=21, 80.8%), hemorrhage (n=15, 57.7%) or calcification (n=3, 11.5%) within the tumor, (3) on the CT or MR images, heterogeneous enhancement pattern presented as peripheral or intra-tumor patchy enhancement was common (n=21, 80.8%). Furthermore, enhanced striped vessels were seen in 12 patients. However, homogenous enhancement pattern was rare (n=5, 19.2%), (4) the most common site where GIST metastasized to was the liver (n=7), followed by the peritoneum (n=4), but rarely to lymph nodes, (5) of these 26 patients, spindle-cell type was observed in 69.2% (n=18), epithelioid-cell type in 23.1% (n=6), and mixed cell type in 7.7% (n=2). Immunohistochemical studies showed positive CD117 expression in all of these 26 patients, but positive CD34 expression in only 22 patients.


CONCLUSIONS
Gastrointestinal stromal tumor usually presents as a exophytic, well-defined large tumor, with internal striped vessels, necrosis or hemorrhage within. It usually metastasizes to the liver or the peritoneum but rarely to lymph nodes. Pathologically, most of gastrointestinal stromal tumors consist of spindle-cells, while a small portion of the tumors are composed of epithelioid-cells or mixed ones. Both CT and MRI play an important role in the diagnosis of gastrointestinal stromal tumors.
Song
Ting
T
Department of Radiology, Third Hospital, Guangzhou Medical College, Guangzhou 510150, China. gzflair@163.com
Shen
Jun
J
Guo
Hao-chang
HC
Liang
Bi-ling
BL
Pan
Heng
H
Jiang
Kui-ming
KM
Xian
Jian-xing
JX
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34 / Q000378:metabolism; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
D018952:Antigens, CD34; D019009:Proto-Oncogene Proteins c-kit