Pulmonary Cyst of Uterine Genesis

Abstract

SESSION TITLE: Fellow Case Report Poster - Imaging SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Benign metastasizing leiomyoma (BML) is a rare disease characterized by well differentiated smooth musle cells of uterine myomatous origin that are present in sites distant from the uterus, most commonly in the lung. Pulmonary BML typically presents as solid discrete nodules of tumor within lung parenchyma in an asymptomatic patient. CASE PRESENTATION: A 65 year old woman presented with episodes of marked diaphoresis for one year. She had history of a hysterectomy for uterine fibroids 17 years prior. Her medical evaluation was unremarkable save for a chest radiograph which identified a left lower lobe mass. Computed tomography of the chest demonstrated a 4.9 cm low density mass along the left major fissure, consistent with a bronchogenic cyst (Figure 1A-B). Also noted were multiple small nodules, 3-6mm in size. The cyst was resected; its cytology was benign and fluid bacterial culture had no growth. The wall of the cyst demonstrated smooth muscle cells staining positive for actin, desmin, as well as estrogen and progesterone receptors, identical to histopathology from her prior hysterectomy. The cyst was also lined by a single layer of cuboidal epithelial cells staining positive for TTF-1 (Figure 2A-F). After cyst removal, the patient reported complete resolution of her symptoms. DISCUSSION: BML lesions are thought to arise as hematogenous metastases from benign tumors, with leiomyomatous smooth muscle cells entering the blood stream during surgical resection. The most well described radiographic presentation is multiple pulmonary nodules with a distribution typical of metastatic lesions. In very rare cases, BML has been reported to present with multiple thin walled pulmonary cysts, invoking the radiographic differential of diffuse cystic lung disease. In these cases,cyst formation is theorized to be due to pulmonary elements entrapped in tumor cells. We believe this case is the first described radiographic presentation of BML consistent with a predominant large fluid filled bronchogenic cyst. While the vast majority of BML nodules are found incidentally in aysmptomatic patients, in this case, the serous filled cyst was associated with pronounced diaphoresis that resolved with cyst resection. CONCLUSIONS: The radiographic differential for localized cystic pulmonary disease should include the rare finding of BML in patients with a history of uterine leiomyomata. Reference #1: Aboualfa K, et al. Benign metastasizing leiomyoma presenting as cystic lung disease: a diagnostic pitfall. Histopathology.2001;59(4):796-799. DISCLOSURE: The following authors have nothing to disclose: Anna Moniodis, Douglas Lin, Paul VanderLaan, Majd Mouded No Product/Research Disclosure Information