چكيده لاتين :
Background: Gastrointestinal stromal tumors (GISTs) constitute
the majority of gastrointestinal mesenchymal tumors.
They usually express a proto-oncogen protein called CD 117
detected by immunohistochemistry. This study investigated the
differentiation of GISTs as well as the risk of aggressive behaviors
in GISTs from surgically-treated patients in university affiliated
hospitals.
Methods: The clinicopathologic, histomorphologic and immunohistochemical
features of 36 GISTs of patients referring to two
large general hospitals in the last 13 years were examined.
Results: The GISTs occurred in 36 patients (41.6% male and
58.4% female) aging 15 to 89 years. 50% of the cases were in the
stomach, 30% in the small intestine and the remainder in the
colon and mesenter. The diameters of tumors were 0.7 to 30 em
and mostly (60.6%) more than 5. 85% of tumor cells were
spindle, 14% epithelioid, and the remainders were mixed. 36.1%
of tumors showed mitotic counts> 5/50 HPF and 11.1 % less than
5/50HPF. 33.3% of the tumors showed necrosis. 8 tumors had
malignant behavior during 13-yrs follow up. Immunoreactivity
for c-kit, SMA, chromogranin, synaptophysin, desmin and S100
were 83.3%, 69.4%, 44.4%, 41.6%, 50% and 0%, respectively.
The decreasing rank order of differentiation forms were neural,
smooth muscle, dual and null. Most of our tumors were in high
risk group and most of the high risks were intestinal with neurogenic
differentiation.
Conclusion: Immunostaining including c-kit is necessary to
study the differentiation of gastrointestinal stromal tumors.
