A 79-year-old man was admitted on the suspicion of acute pancreatitis. Computed tomography showed acute fluid collection but not typical acute pancreatitis; it formed pseudocysts gradually around the pancreas. Endoscopic retrograde pancreatography (ERP) revealed pancreatic disruption and leakage. Endoscopic nasopancreatic drainage (ENPD) and endoscopic pancreatic stenting (EPS) resulted in collapse of pseudocysts, improvement of symptoms and laboratory data, and a mass in the pancreatic body became distinct. The specimens obtained with endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) showed pancreatic cancer. In conclusion, ENPD and EPS are effective for pancreatic leakage with disruption of the pancreatic duct, and we should take into consideration the possibility of pancreatic cancer when we see patients with pancreatic disruption.