Distant metastases from the uterine leiomyoma – case report of a pulmonary benign metastasizing leiomyoma

Benign metastasizing leiomyoma (BML) is a rare condition predominantly affecting women of late reproductive age, characterized by metastasis of the uterine leiomyomas to distant organs. The case is presented of a 48-year-old woman with BML who initially presented with non-specific abdominal pain. She was diagnosed with a uterine tumour and multiple pulmonary metastases. Therefore, uterine sarcoma was suspected. However, pathologic examination of core needle biopsy of the uterine tumour revealed leiomyoma cells. Due to inconsistency between pathologic examination and imaging, hysterectomy was performed. The final pathologic diagnosis confirmed leiomyoma in the uterus. To exclude another malignancy, thoracotomy with open lung biopsy was performed. Histopathological examination showed the same cells as in the uterine leiomyoma, resulting in the diagnosis of BML. Gonadotropin-releasing hormone (GnRH) analog was administered. After 15 months, the patient remained stable without disease progression.