NOT ALL THAT METASTASIZES IS CANCER: A CASE OF BENIGN METASTASIZING LEIOMYOMA

Abstract

SESSION TITLE: Lung Pathology 1 SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Benign metastasizing leiomyoma(BML) is a rare tumor primarily affecting the lungs of late reproductive-aged women with a history of uterine leiomyomas.It has benign histological features, though it metastasizes (biological behavior of malignancy). Immunostains are helpful in diagnosis.They are usually asymptomatic and an incidental finding.A hysterectomy is needed to rule out low grade uterine sarcoma. CASE PRESENTATION: 46F presented with a 2-week history of exertional dyspnea and pleuritic pain. Patient also complained of fatigue. She denied cough, wheezing, constitutional symptoms, leg swelling or orthopnea. Other review of system is nil of significance.Past history includes chronic back pain, incidental lung nodules noted on CT scan following an MVA, and previous tobacco use of <5 pack years and no occupational exposuresPhysical examination revealed a healthy looking female with stable vital signs and otherwise unremarkable examination.CT chest revealed multiple nodules with largest ones in the LUL (2.5cm), RML (2.3cm) and RUL 1.4(cm), compared to prior study nodules had increased in size and number.Prior evaluation of nodules with a CT-guided biopsy was reported as fibrogranulomatous process. Autoimmune workup was negative. Electromagnetic navigation bronchoscopy for biopsy was done revealing reactive appearing bronchial cells and pulmonary macrophages, few crowded cellular groups and no malignant cells. Cultures were negative.PET scan demonstrated nodules with SUV 1.4-1.8 without any abnormal extrathoracic uptake.Surgical lung biopsy was done with wedge resection of left upper lobe. Histology showed cystic, bland-appearing spindle cell neoplasm which was positive for both epithelial (TTF-1 and keratin) and smooth muscle tissue (Desmin and SMA). Cells stained positive for ER/PR, consistent with gynecologic origin leading to diagnosis of leiomyoma.Patient underwent hysterectomy and bilateral salpingoophorectomy showing adenomyosis and intramural leiomyomas. DISCUSSION: Bilateral pulmonary nodules in a late reproductive female can either be benign or malignant. Nodules larger than 1 cm suggest metastatic disease but the chronicity and slow doubling time in this case made malignancy less likely. Benign etiology was favored including granulomatous infection and connective tissue disease, however work up was inconclusive. Results from surgical biopsy was ambiguous given the staining for both smooth muscle and epithelial markers.Lesions vary in size, with smooth well-defined margins and diffuse nonspecific distribution. They are believed to be hematogenous metastases from morphologically benign uterine tumors. With ER/PR positivity in lung lesions, there is the option to treat with hormonal manipulation through surgical or medical oophorectomy. CONCLUSIONS: BML should be a differential diagnosis in females with pulmonary nodules and a history of uterine leiomyoma. Reference #1: Goyle et al; Benign metastasizing leiomyomatosis: case report and review. Am J Clin Oncol. 2003 Oct;26(5):473-6. Reference #2: Eun Young Ki et al; Benign metastasizing leiomyoma of the lung. World J Surg Oncol. 2013; 11: 279. DISCLOSURES: No relevant relationships by Arthur Oliver Romero, source=Web Response No relevant relationships by Cordelia Solomon, source=Web Response