Inhibition of tyrosine kinases by sunitinib associated with focal segmental glomerulosclerosis lesion in addition to thrombotic microangiopathy.

Sunitinib is an orally administered inhibitor of tyrosine kinases and has become the standard of care for many patients with metastatic renal cell carcinoma. Its use has been associated with renal toxicity in some patients. We report a patient with a metastatic clear-cell renal carcinoma who showed arterial hypertension, nephrotic syndrome and azotaemia 10 months after treatment with sunitinib. The renal biopsy revealed focal segmental glomerulosclerosis (FSGS) in addition to thrombotic microangiopathy (TMA), and the complete syndrome disappeared 6 months after sunitinib withdrawal. To our knowledge, this is the first case of FSGS associated to TMA secondary to sunitinib treatment. We discuss the possible glomerular pathomechanism.