Benign "metastasizing" lipoleiomyoma of the uterus

A 62-year-old woman presented with an enlarged uterus and numerous pulmonary nodules. On histological examination, the multiple uterine and lung tumors were lipoleiomyomas and histologically identical. Tumors in both sites were immunoreactive for estrogen and progesterone receptors and had a low MIB index. Although intrapulmonary emboli from a benign lipoleiomyoma of the uterus cannot be entirely excluded, the theory of synchronous multifocal lipoleiomyomatous proliferation may provide a more satisfactory explanation in this case.