Leiomyoma of the lung. Literature review and case report.

Sixty-five cases of pulmonary leiomyomas previously have been reported. A new case is reported of a 23-year-old man. Electron microscopy showed typical ultrastructural smooth muscle differentiation. In a series of 66 cases from the world literature, the ratio of females to males was of 1.5:1. There is a slight preponderance of parenchymal localization versus bronchial. The average age of presentation was 37 years, and the tumor was found rarely in the aged or in children. The diagnosis of pulmonary leiomyoma should be made with the knowledge of recently-introduced concepts of smooth-muscle proliferation in the lung and the possibility that metastatic low-grade leiomyosarcoma may simulate a primary leiomyoma.