Curative Surgery for Metachronous Multiple Liver Metastases from Pancreatic Glucagonoma after Distal Pancreatectomy

Pancreatic glucagonoma is a well-known rare subtype of pancreatic neuroendocrine tumors (PNETs). Most cases of pancreatic glucagonoma are associated with symptoms such as skin rash and necrotizing migratory erythema; however, some cases are asymptomatic. Complete tumor resection has an important impact on the long-term prognosis of patients with primary PNETs. The 2019 edition of the Japanese Guidelines for Neuroendocrine Tumors recommends recurrent lesions of pancreatic and gastrointestinal NETs to be treated multimodally, including resection if the lesions are curatively resectable. However, no treatment strategy has been established for recurrent pancreatic glucagonoma. We report the case of a patient who underwent distal pancreatectomy for primary pancreatic glucagonoma and developed multiple hepatic metastatic recurrences five years after the primary surgery. After two and a half years of somatostatin analog (SSA) treatment, neither tumor growth nor extrahepatic recurrence was detected, and curative surgery was performed. This study reports a rare case of complete resection for multiple metachronous liver metastases from a pancreatic glucagonoma after curative surgery. During SSA therapy, the metastatic tumors showed a very slow growth pattern. No other distant extrahepatic metastases emerged. Curative hepatectomy was performed safely, and the postoperative course was uneventful.