Diffuse Intense Pancreatic Uptake on 99m Tc-HYNIC-TOC SPECT/CT in a Rare Case of Diffuse Pancreatic Neuroendocrine Tumor.

We report a 52-year-old woman with cirrhosis presenting with abdominal pain, and weight loss. During management of cirrhosis-related complications, imaging revealed diffuse pancreatic enlargement with multiple cystic lesions, initially suggesting autoimmune pancreatitis or lymphoma. Subsequent endoscopic ultrasound-guided biopsy confirmed the diagnosis of well-differentiated pancreatic neuroendocrine tumor (PNET). Somatostatin receptor imaging demonstrated intense, diffuse uptake throughout pancreas (Krenning score 4) without local or distant metastases. Despite medical management, her condition deteriorated due to portal hypertension and portal vein thrombosis. This case highlights the importance of recognizing diffuse pancreatic involvement by PNETs on molecular imaging to ensure accurate diagnosis and guide appropriate treatment.