Chronic pancreatitis is mainly a persistent vague or dull pain in the middle or left side of the upper abdomen, with severe pain during episodes and increased pain at night, which can radiate to the lower back or left shoulder. Chronic pancreatitis can form a pancreatic mass that resembles pancreatic cancer, while deep pancreatic tumors compressing the pancreatic duct can cause chronic inflammation of the surrounding pancreatic tissue, which is often misdiagnosed as chronic pancreatitis when taking a biopsy of the pancreatic surface tissue. The diagnosis can be made by puncturing deep tissue biopsy during surgical exploration or using ERCP before surgery.