Pancreas as an Unusual Metastatic Site of Medullary Thyroid Carcinoma: A Case of Very Long-term Follow-up Under Prolonged Treatment with Somatostatin Analogues

Background: Pancreatic metastases from medullary thyroid carcinoma (MTC) are exceptional. Imaging and treatment based on somatostatin receptors may play a role, though the evidence is unconvincing. Case Presentation: We have, herein, documented a unique case of metastatic MTC, where pancreatic metastasis was identified by 68Ga-PET/CT, with the disease showing very slow progression during treatment with lanreotide autogel. A 51-year-old woman underwent total thyroidectomy for goiter in 2000, with a postoperative diagnosis of MTC. Due to persistent disease, somatostatin analogues (SSA) treatment commenced in 2005, following a positive acute octreotide test. In 2012, a pathology-confirmed pancreatic metastasis was diagnosed via 68Gallium-positron emission tomography (68Ga-PET/CT). The disease progressed very slowly over 17 years of SSA treatment. Conclusion: This uncommon case of pancreatic metastasis from MTC indicates that nuclear medicine techniques might offer valuable additional information. Extended treatment with lanreotide autogel appears to correlate with very slow disease progression in selected patients.