Dyspnea in a patient with Mounier-Kuhn syndrome.

Poorly differentiated non-small cell lung carcinoma with a component of sarcoma-like (spindle and/or giant cells) or sarcoma (malignant bone, cartilage, or skeletal muscle) cells are called pleomorphic carcinoma. These carcinoma represent one of the 5 subtypes of rare pulmonary malignancies collectively classified as sarcomatoid carcinoma by the World Health Organization histologic classification of lung tumors. The pathogenesis of sarcomatoid carcinoma remains unclear, and treatment of this malignant tumor is less defined. Very few cases of sarcomatoid carcinoma involving the upper respiratory tract have been reported in the literature. We report here an atypical presentation and location of this tumor (in the trachea), causing obstruction with a positional ball-valve effect, in a patient with tracheobronchomegaly (Mounier-Kuhn syndrome). In addition, we discuss the recurrent nature of the disease and the potential therapeutic difficulties.