Pulmonary benign metastasizing leiomyoma: a report of two cases

Benign metastasizing leiomyoma (BML) is a rare pathological process associated with pelvic leiomyoma. We present two cases of BML that are associated with giant pulmonary metastasis. BML is a rare benign metastatic phenomenon that could easily be mistaken for malignant neoplasms. Both cases occurred in middle-aged women who presented with cough and dyspnea. They previously underwent hysterectomy for uterine leiomyoma. After history taking, computed tomography, integrated PET/computed tomography and pathological assessment, a multidisciplinary treatment was offered for the diagnosis of BML. Physicians should consider BML among the differential diagnoses in women of reproductive age with a history of uterine leiomyoma presenting with pulmonary nodules, and accurate histopathological analysis should be made. Plain language summary: This article reports two cases of a rare pathological process called benign metastasizing leiomyoma. Since it can be mistaken with malignant neoplasm, the report provides evidence and guidance for clinicians and histopathologists to be considered when dealing with similar cases.