Pulmonary benign metastasizing leiomyoma: a case report.

Pulmonary benign metastasizing leiomyoma (PBML) is a rare entity usually occurring in females with history of uterine leiomyoma, and it is preferential to metastasize to the lung and appears as a histopathologic benign tumor of smooth muscle origin. In this article, the clinical and pathological data from 1 patient with PBML were analyzed. Chest CT scan showed that multiple well-defined nodules in the both lobes of the lungs. The tumor cells in the lung were well differentiated, and the pattern of tumor was similar to the original tumor. IHC identified it originated from smooth muscle cells, consistent with the diagnosis of PBML. Positive staining of estrogen and progestogen receptors was detected in both the leiomyoma and the metastasizing lesions. During two years of observation, pulmonary function parameters were within normal limits and there was no evidence of tumor recurrence.