A Glimpse into Lutetium 177 Therapy in Malignant Insulinoma: Case Report and Review of Literature

Background: Insulinomas are a rare type of pancreatic neuroendocrine tumors, characterized by their frequent benign nature and propensity to induce hypoglycemia through excessive insulin secretion. This case report underscores the importance of timely diagnosis and the advantages of a multifaceted therapeutic strategy for treating metastatic malignant insulinomas. This report highlights the promise of somatostatin analogs, chemotherapy, and peptide receptor radionuclide therapy (PRRT) in achieving better patient outcomes.

Case Presentation: A 37-year-old previously healthy woman presented with recurrent hypoglycemia and severe neurological symptoms. Initially misdiagnosed and treated with prednisolone, the patient was eventually admitted to the intensive care unit because of hypoglycemia and hypoxia. Computed tomography revealed a 5.7 cm pancreatic tumor with multifocal liver and spleen metastases. Liver biopsy confirmed a well-differentiated neuroendocrine tumor grade 2. Treatment commenced with continuous glucose infusion and lanreotide and short-acting octreotide injections, followed by palliative chemotherapy (capecitabine and temozolomide). The patient experienced significant clinical improvement, and the subsequent follow-up showed partial resolution of the liver lesions. Further management included peptide receptor radionuclide therapy (PRRT) with Lutetium-177-DOTATATE, which remarkably reduced tumor size and symptoms. The patient maintained euglycemia and clinical stability, with progression-free survival (PFS) exceeding 30 months.

Conclusions: This case highlights the successful management of metastatic malignant insulinoma using a combination of somatostatin analogs, chemotherapy, and PRRT. Sustained clinical improvement and progression-free survival demonstrated the potential of this multimodal approach in controlling the disease and enhancing the patient's quality of life. Further research and guidelines are required to improve the management of metastatic insulinoma. This report emphasizes the importance of considering diverse treatment modalities to provide effective and personalized care for rare and complex endocrine tumors such as malignant insulinoma.