A case of isolated pancreatic sarcoidosis presenting with acute pancreatitis necessitating a differential diagnosis from pancreatic cancer

Sarcoidosis is histopathologically characterized by non-caseating granulomas and can affect any organ; however, pancreatic involvement is rare. We report a case of isolated pancreatic sarcoidosis presenting with acute pancreatitis diagnosed using endoscopic ultrasonographic elastography and endoscopic ultrasonography-guided tissue acquisition. The patient presented abdominal pain and was diagnosed with acute pancreatitis. Computed tomography and magnetic resonance imaging revealed dilation of the main pancreatic duct and a mass in the pancreatic body, raising the suspicion of obstructive pancreatitis secondary to pancreatic cancer. Endoscopic ultrasonography (EUS) was performed following the resolution of pancreatitis and revealed diffuse enlargement of the pancreatic body and tail with the presence of a hypoechoic band. However, the dilatation of the main pancreatic duct and space-occupying lesions observed initially had resolved. EUS elastography demonstrated irregular areas of high and moderate fibrosis, with a shear wave velocity of 2.40 m/s. Pathological examination using EUS-guided tissue acquisition revealed dense lymphocytic infiltration with non-necrotizing epithelioid granulomas. No abnormalities were observed in organs other than the pancreas. The patient was diagnosed with isolated pancreatic sarcoidosis that resolved spontaneously without steroid therapy. Pancreatic sarcoidosis should be considered a potential cause of acute pancreatitis, and EUS elastography is useful for differentiation from other pancreatic diseases.