Mélanome malin pulmonaire : primitif ou métastase ?

Primary pulmonary malignant melanoma is rare (0.01% of pulmonary cancers); only 25 cases are published in the literature. The diagnosis of primary pulmonary malignant melanoma is controversial, the pathogenesis is unknown and a pulmonary metastasis from a mucocutaneous melanoma is the main differential diagnosis. The diagnosis is based on the strict application of the Jensen criteria published in 1967. We report the case of an asymptomatic 82-year-old man presenting with a fortuitously discovered primary pulmonary malignant melanoma according to the Jensen criteria and treated by lobectomy (cT1N0M0). Surgery seems to be the gold standard treatment on account of the poor sensitivity of melanoma to chemotherapy and radiotherapy. Surgical resection and the absence of nodal involvement suggest a good prognosis even though the small number of cases does not produce useful statistical data. This observation raises the question of 18FDG CT-PET in this situation, particularly of the whole body, by extrapolation from the recommendations in mucocutaneous melanoma. The lack of increased uptake on 18FDG CT-PET could be a new paraclinical diagnostic criterion to add to the clinical criteria of Jensen. This report is the first, which shows the results of 18FDG CT-PET (standard and whole-body) under this situation.