Acute respiratory failure mimicking acute respiratory distress syndrome due to parenchymal infiltration by metastatic melanoma.

Malignant melanoma is the most aggressive form of skin cancer and carries a predisposition for metastasis to many different organs. Pulmonary dissemination is common, most often presenting as multiple discrete pulmonary nodules. While a variety of other intrathoracic patterns can occur, diffuse parenchymal infiltration causing acute respiratory failure is an extremely rare manifestation of metastatic disease. We present a case of an otherwise healthy man who developed rapidly progressive respiratory failure mimicking acute respiratory distress syndrome due to melanomatous infiltration of the lung parenchyma and airways.