Pulmonary benign metastasizing leiomyoma: a case report and review of the literature

Pulmonary benign metastasizing leiomyoma characterized by the growth of uterine leiomyoma in the lung is a very rare disease. We herein report the case of a 46-year-old asymptomatic woman who underwent a total abdominal hysterectomy for her multiple uterine leiomyomas 5 years ago, with the presence of multiple shadows in her chest roentgenogram during the regular check-up. Chest computerized tomography (CT) showed multiple solitary nodules in both lungs. Video-assisted thoracoscopic surgery with a wedge resection of the lesion was performed. Histopathologically, the pulmonary nodule was composed of benign smooth muscle cells and demonstrated low mitotic activity and absence of necrosis. Immunohistochemical staining for smooth muscle actin (SMA) and Desmin were extremely positive. CD10, CD117 and S-100 were negative in the tumor cells. Positive immunoreactivity for estrogen receptor (ER) and progesterone receptor (PR) were detected. The pathological diagnosis was pulmonary benign metastasizing leiomyoma.