[Angiomyolipoma of the lung]

We present a case of a 48 year old man who complained of progressive dyspnoea. Radiograph revealed a large tumor in the left lung. Biopsy was performed and revealed beneath a normal bronchial epithelium polymorph tumor cells admixed with some histiocytes. These tumor cells were strongly pigmented and expressed HMB-45 and protein S-100 immunohistochemically. Malignant melanoma of the bronchus was included in the differential diagnosis. A thoracotomy and left lower lobe resection was performed. Histology revealed an angiomyolipoma. The lung is an uncommon localisation of angiomyolipoma with so far three reported cases. Lipoma, leiomyoma and lymphangioleiomyomatosis have to be included in the differential diagnosis. The peculiarity of this case is the presence of multiple pigmented tumor cells that express HMB-45. This has not been reported yet.