Gastrointestinal stromal tumor: a rare abdominal tumor.

Gastrointestinal stromal tumors (GISTs) are rare abdominal tumors which arise from the interstitial cells of Cajal in the gastrointestinal tract. Gastric GISTs are the most commonly seen GIST tumors and may grow to a very large size. They are often associated with abdominal pain, anorexia and weight loss. Most of them can be detected by CT. These tumors have been found to harbor mutations in CD117 which causes constitutional activation of the tyrosine kinase signaling pathway and is considered to be pathognomic. Tyrosine kinase inhibitors such as imatinib have revolutionized the treatment of these tumors, which are otherwise resistant to conventional chemotherapy and radiotherapy. Although surgical resection is the mainstay of treatment, tyrosine kinase inhibitors have been useful in prolonging the recurrence-free survival of these patients. Resistance to imatinib has been reported in GISTs with specific mutations. We present a case of gastric GIST which grew to a very large size and was associated with abdominal pain and weight loss. It was successfully resected and the patient was commenced on imatinib therapy.