Hepatic and peritoneal metastases are the most frequent metastatic lesions in 
patients with gastrointestinal stromal tumors (GIST), and may result in intra- 
or extrahepatic cholestasis and altered drug metabolism. While the tyrosine 
kinase inhibitor imatinib, which has been recently shown to represent the 
treatment of choice for GIST, is primarily metabolized by the liver, data on the 
pharmacokinetics and the tolerability of imatinib in patients with increased 
cholestasis parameters are not yet available. We here report on two patients who 
received imatinib in the presence of increased bilirubin and/or cholestasis 
parameters. With a follow-up duration of 3-4 months, we observed no toxicities 
outside of well-known side effects including some degree of myelosuppression and 
fluid retention. This report may aid in the decision of imatinib being given 
under close surveillance to this kind of patients.