[Ectopic pancreatic tissue within a mediastinal cyst--a rare clinical manifestation]

We describe the case of a patient aged 25 years showing the rare finding of a mediastinal tumour containing ectopic pancreatic -tissue (maximum diameter of 15 cm). At admission, the patient presented with symptoms comparable to those of pneumonia. A computed tomographic scan of the thorax confirmed an -extensive mediastinal mass. A transthoracic puncture aspiration followed by a cytological examination failed to provide information of diagnostical relevance. OPERATION: To resect the mass and its adjacent tissue completely, a posterolateral thoracotomy on the left side was performed. The histopathological examination revealed exo- and endocrinic pancreatic tissue and a pancreatic pseudocyst with-out a thoracopancreatic fistula.

The incidence of mediastinal cysts containing pancreatic tissue seems to be extremely low. Above all, our case is the only one presenting clinical symptoms of a lobar pneumonia. In consideration of the current literature, we give a description of histological pattern, the possible pathogenesis and classification.

Surgical therapy provides the chance for tumour removal. It provides an excellent outcome when performed completely.