Spontaneous regression of pulmonary leiomyomas during pregnancy

Multiple pulmonary nodular densities simulating metastastic cancer were discovered in a routine chest roentgenogram of a 30-year-old pregnant woman. Lung biopsy revealed nodules composed of smooth muscle and collagenous tissue containing entrapped glandular elements. The lesions were initially interpreted as multiple pulmonary fibroleiomyomatous hamartomas (MPFLH). During pregnancy and the post-partum period, the pulmonary nodules regressed spontaneously. Critical analysis of the published cases as well as our own case indicates that multiple pulmonary fibroleiomyomatous hamartomas (MPFLH) cannot be distinguished from benign metastasizing leiomyoma (BML) by either clinical, roentgenographic, or pathologic criteria and that all represent pulmonary metastases from a primary uterine neoplasm. The spontaneous regression of the pulmonary nodules in the present case as well as the increased risk for development of progressive pulmonary insufficiency in the pre-menopausal patients indicates an apparent hormonal dependence. Total abdominal hysterectomy and bilateral salpingo-oophorectomy appears to be the treatment of choice.