Dermatomyositis with subclinical myositis and spontaneous pneumomediastinum with pneumothorax: case report and review of the literature.

Dermatomyositis (DM) is a clinical entity characterized by a distinctive cutaneous rash and inflammatory myopathy. Besides skin and muscle, the disease can also involve other internal organs, especially the lungs. We describe a patient with dermatomyositis and incomplete signs of myositis who developed pneumomediastinum, pneumothorax and massive subcutaneous emphysema. This case illustrates a rare pulmonary complication of DM, and underscores that muscular involvement in this disease is not always reflected in laboratory and/or histological abnormalities.