Benign Metastasizing Leiomyoma in a Patient With No Known History of Uterine Leiomyomas

Benign metastasizing leiomyoma (BML) is a rare medical condition characterized by metastasis of fibroid tissue from uterine leiomyomas to other areas of the body, most commonly the lungs. While BML is mostly prevalent in women with a prior history of uterine leiomyomas who underwent surgical intervention, this case report explores the case of a 50-year-old female who was diagnosed with pulmonary benign metastasizing leiomyoma (PBML) with no prior history of confirmed leiomyomas. After initially presenting with worsening cough and congestion, chest radiograph and computed tomography revealed multiple bilateral pulmonary nodules, initially raising concerns for malignancy. Further, a workup with bronchoscopy with fine needle aspiration and pulmonary lesion biopsy revealed the presence of smooth muscle tissue suggestive of PBML. Subsequent uterine ultrasonography revealed a 3-cm intramural uterine fibroid, supporting the diagnosis. This case highlights the diagnostic challenge posed by PBML due to its asymptomatic manifestation and radiological similarity with other serious conditions such as malignancy and sarcoidosis. The case further highlights the importance of recognizing typical radiological features of PBML and the necessity of histological examination for accurate diagnosis. Finally, the critical role of a multidisciplinary approach in managing such rare conditions and the need for individualized treatment are also explored.