Pulmonary benign metastasising leiomyoma: a single-institution case series

Abstract

Benign metastasising leiomyoma (BML) is a rare and often asymptomatic presentation of smooth muscle tumour of uterine origin, occurring outside the uterus. We present the first case series of pulmonary BML in a contemporary UK population. Patients were identified from prospective histopathological databases spanning from 2003 to 2019. Data was collected retrospectively from physical and electronic data sources. Six post-menopausal females were identified with an average age of 44±8 years (mean±SD). Fifty percent of our cohort was asymptomatic with an incidental finding of pulmonary nodules, whilst the others complained of non-specific respiratory symptoms. Five patients (88%) had multiple lesions (median 9, range 2 to 12)—with bilateral distribution, measuring an average of 11 mm (range 7 to 27) in size on cross-sectional imaging. All patients underwent diagnostic surgical pulmonary wedge resection, with no perioperative morbidity. Immunohistochemistry confirmed the presence of ‘spindle cells’, staining positive for smooth muscle actin, desmin and progesterone receptors for all patients (100%), and oestrogen receptors in five patients (87%). Four patients (67%) underwent a hysterectomy prior to diagnosis of BML and one (17%) due to the diagnosis itself. Four patients (67%) underwent oophorectomy, whilst one patient required hormonal suppression therapy. Survival was 100% at a median follow-up of 59.5 months (range 29 to 166). BML is a rare clinical entity accounting for a small proportion of patients presenting with pulmonary nodules. Following successful tissue diagnosis, outcomes with conservative or medical management are excellent.