SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Tuberous Sclerosis Complex (TSC) is a multisystem, autosomal-dominant condition that is associated with the development of Lymphangioleiomyomatosis (LAM). Estrogen is thought to play an important role in the pathogenesis of LAM. Increased estrogen levels during pregnancy likely contribute to the progression of LAM and the development of complications. We present a case of TSC-LAM with recurrent pneumothoraces (PTX) during pregnancy. CASE PRESENTATION: A 19-year-old gravida 1, para 0 Hispanic female with past history of TSC with known neurologic, ocular, renal, and pulmonary involvement presented with dyspnea at 24 weeks gestation to the emergency department. On presentation, patient was dyspneic but saturating well on room air, heart regular, rate and rhythm with bilateral chest expansion with decreased lung sounds on right. Chest radiograph showed right-sided PTX requiring chest tube placement. She had resolution of PTX within a few days and was discharged home. Shortly thereafter, she was readmitted with a left-sided PTX again requiring chest tube placement. Chest tube was removed after a few days with plans for pleurodesis following delivery. However, she was again readmitted now at 32nd weeks gestation with another right-sided PTX requiring chest tube placement. Due to failed clamping trials with reoccurrence of symptoms over the next two weeks, a PneumostatTM chest valve drain was placed and patient was transferred to the Obstetrics ward for continued observation. Eventually, the patient underwent a planned primary cesarean section at 38 weeks with delivery of a healthy boy. The patient did well post-operatively with plans for a future surgical pleurodesis. DISCUSSION: Pneumothoraces occur in approximately 60-70% of patients with LAM with recurrence rates over 70%. Because LAM occurs mainly in women of reproductive age, it is hypothesized that estrogen is involved in the abnormal smooth muscle proliferation. Therefore, pregnancy, a high estrogen state, is thought to increase risk of PTX in patients with LAM. While there are long term treatment options with mTOR inhibitors, such as sirolimus (pregnancy category class C), in patients with progressive lung function decline, there is a lack of literature regarding management of LAM complications during pregnancy. CONCLUSIONS: We highlight that a chest valve drain may be a viable alternative to surgical pleurodesis as a bridge to delivery in a patient concerned about surgical risk during pregnancy. This case helps solidify the need for discussion regarding the management of complications in LAM patients who become pregnant. Reference #1: Lymphangioleiomyomatosis (LAM). Breathe (Sheff). 2017;13(1):64-71. DISCLOSURES: No relevant relationships by Angela Birdwell, source=Web Response no disclosure on file for Sheila Habib; No relevant relationships by Tasnim Islam, source=Web Response Consultant relationship with Sunovion Please note: $1001 - $5000 Added 11/28/2018 by Diego Maselli Caceres, source=Web Response, value=Consulting fee Consultant relationship with Sanofi Regeneron Please note: $5001 - $20000 Added 11/28/2018 by Diego Maselli Caceres, source=Web Response, value=Consulting fee Consultant relationship with AztraZeneca Please note: $1001 - $5000 Added 03/14/2019 by Diego Maselli Caceres, source=Web Response, value=Consulting fee Consultant relationship with Novartis Please note: $1001 - $5000 Added 03/14/2019 by Diego Maselli Caceres, source=Web Response, value=Consulting fee Consultant relationship with GSK Please note: $5001 - $20000 Added 03/14/2019 by Diego Maselli Caceres, source=Web Response, value=Consulting fee No relevant relationships by Maria Velez, source=Web Response No relevant relationships by Robert Winsett, source=Web Response