Lenvatinib-induced tumor lysis syndrome in a patient with advanced hepatocellular carcinoma: a case report.

Tumor lysis syndrome (TLS) is an oncologic emergency caused by release of intracellular tumor components due to massive tumor lysis and is rare in patients with hepatocellular carcinoma (HCC). We describe a case of TLS with rupture of HCC induced by lenvatinib in a patient with advanced HCC. A 72-year-old man who presented with right upper abdominal pain was diagnosed as having advanced HCC with a high tumor burden by contrast-enhanced computed tomography and percutaneous hepatic tumor biopsy. He was started on lenvatinib 12 mg once daily when his tumor progressed despite one-shot hepatic arterial infusion chemotherapy. On day 2 of treatment with lenvatinib, he developed severe upper abdominal pain and was diagnosed as having TLS with HCC rupture by laboratory tests and contrast-enhanced computed tomography. Urgent treatment with transarterial embolization, hemodialysis, and blood transfusion therapy was successful. The patient was then restarted on oral lenvatinib at a reduced dose without recurrence of TLS. TLS is a rare potential complication of lenvatinib in patients with advanced HCC and a high tumor burden.