BACKGROUND: Gastrointestinal stromal tumours (GISTs) are the most common 
mesenchymal tumours of the gastrointestinal tract. They are positive to C-kit 
(CD 117), more common in the older males, and mostly in the stomach, less in the 
colon and rectum and oesophagus. Benign tumours are more common than the 
malignant ones. Classification of GISTs is based on morphology and 
immunochemistry.
METHODS: We report two cases of colorectal gastrointestinal mesenchymal tumours, 
one on the transverse colon which was found to be immunohistochemically 
leiomyosarcoma and the other on the rectum which met the GIST criteria. The 
patients underwent transversectomy and abdominal perineal resection, 
respectively.
CONCLUSIONS: They did not receive Imanitib postoperatively and two years after 
there is no evidence of recurrence. Surgery is the treatment of choice for 
resectable GISTs, and other mesenchymal tumours benign or malignant.