We described a 41-year-old woman with dermatomyositis, interstitial lung disease, and cutaneous vasculopathy who developed a pneumomediastinum. The routine bronchoscopy investigation found pale lesions in the larynx, that extended to the tracheobronchial tree, and deep ulcers in the membranous wall of the trachea. The histopathology examination revealed an inflammatory process that was diagnosed secondary to the vasculitis, but no infections. Superior and inferior airway lesions in the same patient with dermatomyositis is a very rare condition. The association of dermatomyositis with deep mucosal ulcers and pneumomediastinum is not clear, but a bronchoscopic examination should be used to improve evaluation.