Incidental Finding of Synchronous, Benign, Metastasizing Leiomyoma with Distinct Cytogenetics in the Lung and Uterus.

This paper will present a case of benign metastasizing leiomyoma, incidentally found during the preoperative evaluation for acute cholecystitis. The preoperative chest X-ray revealed diffuse bilateral lung nodules suspicious for hematogenous metastasis and the densities measured 1-1.5 cm. A pelvis computed tomography (CT) scan showed in-homogeneous uterine mass with unusual vascular supply raising concern for leiomyosarcoma. Open lung biopsy revealed benign-appearing smooth-muscle neoplasm suggestive of metastatic leiomyoma. The patient was then treated with total abdominal hysterectomy with bilateral salpingo-oopherectomy which had identical pathology to the lung. As there were innumerable pulmonary metastases where complete resection was impossible, surgical castration appeared to be effective in reducing tumor size. The patient was also started on an aromatase inhibitor that subsequently improved her clinical outcome. Management strategies, cytogenetics, and histological diagnosis are discussed.