CT findings of pathology proven benign metastasizing leiomyoma

Benign metastasizing leiomyoma, originally reported in 1934 by Paul Steiner is a rare entity with less than 150 documented cases. While this entity has a favorable prognosis, without proper recognition it could be misdiagnosed as advanced stage metastasis. This case report discusses the relevant imaging findings of a case of benign metastasizing leiomyoma involving a 46-year-old woman which was detected in a preoperative work-up for hysterectomy. The patient presented with chronic cough for 2 years and a history of uterine fibroids. Because benign metastasizing leiomyoma was considered in this patient who presented with lung nodules and pelvic masses, a biopsy of the salient lesions was rapidly performed and enabled pathology to confirm a diagnosis of this entity. This case examines the differential diagnoses associated with multiple pulmonary nodules and provides an example of why the radiologist should consider benign metastasizing leiomyoma in that differential when these findings are identified in perimenopausal women.