Gastric stromal sarcomas: correlation of MR imaging and histopathologic findings in nine patients.
OBJECTIVE
To define the appearance of gastric stromal sarcomas at magnetic resonance (MR) imaging.


METHODS
Nine patients with gastric stromal sarcoma underwent MR imaging with the following sequences: nonenhanced and gadolinium-enhanced breath-hold, T1-weighted, spoiled gradient-recalled echo (n = 9); fat-suppressed, T2-weighted, fast spin echo (n = 9); and breathing-independent, half-Fourier rapid acquisition with relaxation enhancement (n = 6). Lesion morphology, signal intensity features, and relationships to the gastric wall and surrounding organs were retrospectively evaluated. The diagnosis of gastric stromal sarcoma was histologically proved in all patients.


RESULTS
The nine tumors were solitary, multilobulated, shaped irregularly, predominantly exophytic, and large (diameter range, 7-28 cm [mean, 15.8 cm]). The epicenters of all lesions were extrinsic to the stomach, and all lesions arose from the gastric cardia or body. Regions of necrosis and hemorrhage were detected in all cases. Marginal definition on MR images corresponded to histologic grade: High-grade neoplasms possessed ill-defined margins, and low-grade neoplasms demonstrated more well-defined margins. Relationships to surrounding organs depicted at MR imaging corresponded well with histopathologic findings.


CONCLUSIONS
Gastric stromal sarcomas demonstrate characteristic MR imaging features, which correspond well with histopathologic findings. The direct multiplanar capability of MR imaging facilitates delineation of relationships of the tumors to the stomach and surrounding organs.
Department of Radiology, Hamamatsu Medical Center, Japan.
S
S
Hasegawa
R C
RC
Semelka
T C
TC
Noone
J T
JT
Woosley
H B
HB
Marcos
P J
PJ
Kenney
E S
ES
Siegelman
D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018203:Sarcoma, Endometrial Stromal / Q000175:diagnosis* / Q000473:pathology; D012680:Sensitivity and Specificity; D013270:Stomach / Q000473:pathology; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000473:pathology
D003287:Contrast Media