[Two cases of spontaneous pneumomediastinum due to Xiao-lin Temple boxing vocal exercise].

Two cases of spontaneous pneumomediastinum and subcutaneous emphysema were reported. The first cases was a 21-year-old man who had a past history of recurrent spontaneous pneumothorax. The second was a healthy 20-year-old man. They were admitted to our hospital because of dyspnea and chest pain, which occurred at or after vocal exercise for Xiao-lin Temple boxing. Physically, a mediastinal crunch on auscultation heard over the cardiac apex and the left sternal border (Hamman's sign) was recognized in the first case, and subcutaneous emphysema was palpated in both cases. The chest X-ray films revealed intramediastinal air and subcutaneous emphysema in both cases. We diagnosed these patients as spontaneous pneumomediastinum because of no underlying disease. This is a report of rare cases of spontaneous pneumomediastinum occurring at the same time, and one of the mechanism causing them was considered to be a sudden increase in intrathoracic pressure due to the vocal exercise of chinese boxing.