Nephrotic syndrome as a manifestation of thrombotic microangiopathy due to long-term use of sunitinib.

Nephrotic syndrome in patients with cancer may be related to the primary malignancy or chemotherapeutic therapy. Solid organ cancers may cause membranous glomerulonephritis which is manifested by nephrotic syndrome; other less common histologic presentations include focal and segmental glomerulosclerosis and minimal change disease. In addition, chemotherapy agents may cause renal toxicity by affecting the small blood vessels, glomeruli, tubules, and interstitium. Tyrosine kinase inhibitors such as sunitinib may cause endothelial and podocyte damage leading to thrombotic microangiopathy affecting only the kidney and manifested by proteinuria and hypertension. We report a case of an elderly man with gastrointestinal stromal tumor (GIST) on treatment with sunitinib who had as a complication a thrombotic microangiopathy manifested with nephrotic syndrome and a hypertension of difficult control, which was finally controlled by stopping this drug but had a fatal outcome due to its malignancy.