Lenvatinib-Induced Acute Pancreatitis in a Patient with Metastatic Thyroid Cancer: A Case Report

BACKGROUND: Lenvatinib, a novel multi-target tyrosine kinase inhibitor, has been approved for treating differentiated thyroid cancer. Herein, we describe a rare case of acute pancreatitis that developed during lenvatinib treatment in a 65-year-old man with recurrent thyroid cancer. CASE PRESENTATION: The patient was admitted to our department following a complaint of acute-onset epigastric pain and indigestion. He had been receiving lenvatinib since 34 days. Although his serum amylase and lipase levels were normal, he had acute-onset persistent epigastric pain and typical computed tomography findings, which were consistent with those of acute pancreatitis. As other common etiologies were excluded, it was concluded that the patient had lenvatinib-induced acute pancreatitis. On admission day 14, he could consume food orally, after conservative care, including drug cessation, intravenous hydration, and pain control. CONCLUSION: Physicians should consider acute pancreatitis as a differential diagnosis for patients complaining of abdominal pain while on lenvatinib, regardless of hyperamylasemia or hyperlipasemia. Systematic collection of data on acute pancreatitis development during lenvatinib treatment should be considered, and further research is warranted to identify the mechanism of acute pancreatitis associated with multi-target tyrosine kinase inhibitors such as lenvatinib.