Gastrointestinal stromal tumors. A clinicopathological study.

OBJECTIVES: To evaluate the clinical presentations and immunohistochemical (IHC) properties of gastrointestinal stromal tumors (GISTs) and to compare them to internationally published data.

METHODS: Thirty-six patients diagnosed with GISTs between January 1997 and December 2015 were retrospectively studied in 2 tertiary hospitals. Immunohistochemical staining was carried out prospectively when it has not been completed fully at the beginning. Results: The median age of patients was 54 years  (range; 17-81 years). Predominantly, we found more females were affected. The male to female ratio was 1:1.7. The most frequently affected organs were the stomach (63.8%) followed by small bowel (25%) and colorectal region (8.4%). Abdominal pain was the most frequent presentation in 33.3% of the patients then gastrointestinal (GI) bleeding in 30.5%. Most of the gastric GISTs were at early stages at presentation: stage 1 and II (60.8%), while in non-gastric GISTs, the tumor stage was advanced: stage III and IV (69.3%). The IHC characteristic of GIST in descending order showed positivity for vimentin (88.9%), CD117 (83.3%), CD34 (77.8%), Ki67 (63.9%), SMA (38.9%), desmin (27.8%), and S100 (19.4%).

CONCLUSION: Gastrointestinal stromal tumors in our study demonstrates a major similar feature as the published international data. However, minor differences do exist in terms of clinical features and immunohistochemistry.