Leiomyomas of the lower respiratory tract.

Leiomyomas account for about 2% of benign tumours of the lower respiratory tract. From the relatively few cases reported in the literature, it appears that these tumours most commonly occur in the fourth decade, although one third of patients are under the age of 20 years. The distribution of leiomyomas favours the distal part of the tracheobronchial tree and the most common site for tracheal lesions is the membranous portion of the lower third. Over 90% of pulmonary parenchymal leiomyomas, which themselves are more common in women, are incidental findings on chest radiographs whereas bronchial lesions are important causes of irreversible lung damage. Tracheal lesions may present as bronchial asthma. Accurate early diagnosis rests on a high index of clinical suspicion and histological examination of bronchoscopic biopsy specimens or frozen section material obtained at exploratory thoracotomy. Treatment could be conservative surgery, but 65% of reported cases have been managed by lobectomy or pneumonectomy as a result of advanced irreversible lung disease or unawareness of the benign nature of the lesion.