Mucin-producing tumor of the pancreas associated with pyothorax: report of a case.

We report herein the case of a 76-year-old man for whom an invasive mucin-producing tumor of the pancreas (MPTP) was successfully treated by surgery. A cystic lesion of the pancreas had been found by computed tomography (CT) 9 years earlier, 2 years following which suction drainage for left pyothorax had been carried out. A pancreatic cyst fistula to the thorax had subsequently been found during decortication for recurrent pyothorax 2 years later. Methicillin-resistant Staphylococcus aureus was detected in the pleural discharge after the thoracotomy, and thoracic fenestration was performed. A CT scan done 4 years later showed enlargement of the pancreatic cysts and a cystography revealed communication to the duodenum via the main pancreatic duct. Endoscopic retrograde cholangiopancreatography (ERCP) showed dilatation of the main pancreatic duct. The pancreatic cyst fistulated to the stomach and to the fenestrated thorax. Since MPTP was suspected from this clinical course, a distal pancreatectomy, partial gastrectomy, and omentopexy to the thorax were performed. The pathological diagnosis was intraductal papillary-mucinous tumor of the pancreas with a megacyst. While MPTP is recognized as a low-grade malignancy, some cases of invasive disease have been reported. To the best of our knowledge, this is the first case of MPTP associated with pyothorax due to fistula formation.