The differential diagnoses of multiple lung masses are diverse, with metastatic disease being the most common etiologic consideration. Other causes include Sarcoidosis, lung infections with Mycobacteria, Fungi, Nocardia or Septic emboli. In asymptomatic patients, other possibilities include amyloidosis, rheumatoid nodules, arteriovenous malformations, hamartomas and smooth muscle tumors.
A 50-year-old Hispanic woman with mild persistent asthma presented to the ER with complaints of increasing dyspnea and chest tightness over 3 days. She also had a cough productive of bloodstained whitish sputum, orthopnea, paroxysmal nocturnal dyspnea and recurrent leg swelling. She reported no constitutional symptoms. Her medications included fluticasone and albuterol MDI. Her past medical history was remarkable only for a hysterectomy. She did not smoke or report any illicit drug abuse. Her physical examination was unremarkable. Laboratory examination demonstrated an ESR of 50 mm/hr. The serum carcinoembryonic antigen level was normal (0.52 ng/ml). Blood gas on room air was normal. The chest radiograph demonstrated multiple rounded opacities in both lung fields with pleural thickening noted in the right major and minor fissures. The CT scan of the chest with contrast revealed multiple masses of varying sizes involving all the lobes of the lungs. The hilar and mediastinal structures were normal without lymphadenopathy. Fiberoptic bronchoscopy revealed an endobronchial lesion in the superior segment of the right lower lobe. Trans-bronchial biopsy showed an undifferentiated spindle cell tumor. Immunocytochemistry was positive for Desmin and SMA stains indicating smooth muscle differentiation.
The biopsy was consistent with benign metastasizing leiomyoma (BML). BML is a rare disease entity with only 75 cases reported in the literature; most reports have involved Asian women. BML is commonly seen in the lungs. Other sites of involvement include lymph nodes, peritoneum and retroperitoneal structures. Myocardial, ocular, brain and spinal cord involvement have also been reported. The pathogenesis of BML is controversial. It is thought that the disease is metastatic from a low-grade leiomyosarcoma or leiomyoma and that it seeds the lungs via the bloodstream during surgery. The occurrence of lung nodules have been reported between 3 months and 20 years after surgery, although a single case of simultaneous presentation of leiomyomas in the uterus and lungs has been reported. The clinical course of BML is indolent with patient death commonly due to an unrelated disease condition. Radiological features of BML include well-circumscribed single or numerous non-calcified nodules of variable sizes interspersed within normal parenchyma. The identification of estrogen and progesterone receptors in the lesions has therapeutic implications, as the lung lesions have been known to occasionally regress with surgical or medical oophorectomy. Menopause has also been associated with lesion regression. The diagnosis was supported by the presence of incidental finding of lung nodules, history of uterine fibroids and hysterectomy and the absence of a primary malignant disease.
This case represents the first occurrence of endobronchial BML and the first report of BML in a patient of Hispanic origin. BML should be considered in the differential diagnosis of female patients who present with multiple lung nodules regardless of ethnicity.
S.K. Dartey-Hayford, None.