Characteristics of gastrointestinal stromal tumors in a Middle Eastern population.

OBJECTIVE To demonstrate the immunohistochemical and epidemiological characteristics of gastrointestinal stromal tumors (GIST) in a Middle Eastern population. METHODS This is a retrospective analysis of all intra-abdominal mesenchymal tumors (excluding childhood embryonal rhabdomyosarcoma and small round blue cell tumors) collected from the archives of the Pathology Departments of King Hussein Cancer Center, Amman, and King Abdullah University Hospital, Irbid, Jordan between 2001 and 2008. The immunohistochemical profile of all cases was studied at King Hussein Cancer Center, Amman, Jordan, between January and August 2009. RESULTS Gastrointestinal stromal tumors comprised 45% of the intra-abdominal mesenchymal tumors (42 out of 93 cases), with the most common site being the stomach (n=17, 40.5%). Twenty-seven GIST cases (64.3%) were classified as high risk, 4 (9.5%) as intermediate risk, 6 (14.3%) as low risk, and 2 (4.8%) as very low risk. Immunohistochemistry showed diffuse and strong positivity (+3) for CD117 in 85.7% of GIST cases, and for CD34 in 65% of cases. The high-risk tumors were more common in male patients (M:F=1.7:1), while the non-high risk tumors were more common in female patients. CONCLUSION The immunohistochemical profile of GIST in Jordanian patients is similar to previously published data from other populations, with a slight male preponderance for high-risk GISTs.