Blue toe syndrome and sunitinib.

We present a patient with metastatic renal cell carcinoma treated with sunitinib, a multitargeted tyrosine kinase inhibitor. The patient experienced bilateral blue toe syndrome which we related to sunitinib use. Discontinuation of sunitinib to lower the patient's prothrombotic state and increase the ability to form collaterals, together with the addition of low-molecular-weight heparin to treat the occluding thrombi, resulted in waning of the blue toe syndrome. This case adds to the accumulating evidence of possible untoward cardiovascular side effects that should be taken into consideration in patients on tyrosine kinase inhibitors such as sunitinib.