[Primary alveolar soft part sarcoma of the lung]. / Sarcome alvéolaire primitif du poumon.

BACKGROUND: Alveolar soft part sarcoma is rare; it mainly appears in the lower extremities in adults and the head and neck in children. Primary pulmonary occurrence of this tumour is exceptional. OBSERVATION: We report a new case in a 49-year-old man who presented with thoracic pain developing over one month. Imaging showed a tumour in the left upper lobe. Diagnosis of primary alveolar sarcoma of the lung was made by histological examination of a biopsy specimen and elimination of a primary soft tissue tumour elsewhere. CONCLUSION: Primary alveolar sarcoma of the lung is exceptionally rare and the diagnosis should only be made after eliminating a soft tissue tumour elsewhere.