Mucinous cystadenomas of the pancreas are rare tumors appearing usually within the body and the tail of the pancreas in a young and middle-aged women. They rarely communicate with the pancreatic duct and occasionally may become malignant. The authors present a patient with a number of rare features. In a 52-year-old male, we did a radical pylorus-preserving cephalic duodenopancreatectomy for a mucinous cystadenoma within the head of the pancreas, which perforated into the main pancreatic duct causing chronic obstructive pancreatitis having few foci of malignant alteration. The postoperative recovery was uneventful, but three months later the patient died due to exacerbation of the underlying serious heart disease.