Multiple lung tumors found 17 years after hysterectomy —A case of benign metastasizing leiomyoma—

The patient is a 50-year-old female who presented with cough. A chest X-ray showed bilateral multiple nodular shadows. Even though a diagnosis of metastatic lung tumors was strongly suspected, no primary lesion could be detected on close examination. Therefore, an exploratory thoracotomy, and histopathological examination of a specimen obtained from a resected tumor were carried out. The resected tumor revealed pathological proliferation of spindle cells without high cellularity or mitosis with nuclear atypism. The patient had a history of surgery for uterine leiomyoma at the age of 33. The histopathological characteristics of the resected lung tumors were remarkably similar to those of the previously resected uterine leiomyoma. In addition, the serum levels of sex hormones, including LH, measured after lung surgery, were within normal range suggesting the possibility of the lung tumors being metastatic. The residual lung tumors did not show any increase in size 26 months after surgery. Therefore, these lung tumors could be considered as lung metastases from a low grade malignant uterine leiomyoma (benign metastasizing leiomyoma). (benign metastasizing leiomyoma).