[Pulmonary hamartoma with lipomatous form]

We report of the case of a 41-year-old patient, who had previously undergone thoracic surgery at the age of 16 for a single giant emphysematous bulla. The CT scan showed an abnormal middle mediastinal lesion containing an aerated cystic areas and areas of fat density. The patient underwent surgery and a well-defined mass was found between the mediastinum and the pulmonary hilum, which was able to be completely resected. Microscopic examination disclosed a composite tumour containing a bronchogenic cyst, a benign lipoma and two hamartochondromas. As no similar case had been reported previously, it was difficult to assert the nature of the lesion, which has been labelled as a "hamartoma". The main diagnoses which should be considered when an intra pulmonary fat density mass is disclosed, are discussed.