A CASE OF BIRT-HOGG-DUBE SYNDROME PRESENTING AS RECURRENT SPONTANEOUS PNEUMOTHORACES

Abstract

SESSION TITLE: Medical Student/Resident Lung Pathology SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Birt-Hogg-Dube (BHD) is a rare hereditary syndrome inherited through an autosomal dominant mutation in the FLCN gene resulting in the loss of function of the protein folliculin. While the exaction function is unknown, this protein is thought to interact with multiple protein kinases responsible for tumor suppression. This syndrome affects multiple organ systems manifesting in benign dermatologic tumors, multifocal renal tumors and characteristic cystic lung disease which can result in recurrent secondary spontaneous pneumothoraces. There are no current treatments for BHD and management consists of active surveillance for renal tumors and lifestyle changes to reduce risk for spontaneous pneumothorax. Here we present a case of a male patient presenting with recurrent spontaneous pneumothoraces, ultimately diagnosed with BHD. CASE PRESENTATION: A 67-year-old old male with history of prostate cancer treated with radical prostatectomy in remission, multiple skin tags, coronary artery disease, hypertension and a twenty pack-year smoking history presented with acute onset dyspnea secondary to a spontaneous right sided pneumothorax which was treated with a tube thoracostomy with resolution. Over the next month he had two additional recurrent right-sided pneumothoraces, discharged both times with Heimlich valves and both later removed on outpatient follow-up. He was offered, but refused pleurodesis. During his third admission, a CT scan showed an axillary intramuscular lipoma as well as multiple cystic lesions in the liver, kidneys and lungs. Chest imaging two years prior had shown cystic lesions thought to represent emphysema. Given this constellation of skin, renal and lung pathology, he was referred for a genetic evaluation, which was significant for a heterozygous mutation of the FLCN allele consistent with BHD syndrome. Pulmonary function testing showed a mild restrictive ventilatory defect. Despite protracted complaints of dyspnea, the patient gradually returned to his baseline functional status. DISCUSSION: The clinical manifestations of BHD are highly variable between individuals and families and the true incidence of this syndrome is unknown. Our patient had no known family members with clinical signs of BHD. Though he previously had undergone multiple procedures to remove his skin lesions, BHD was not suspected until he had multiple recurrent spontaneous pneumothoraces. Additionally, our patient had undergone regular CT scans for lung cancer screening showing centrilobular cystic lesions, assumed to be secondary to emphysema. Though a rare disorder, providers should suspect BHD in patients presenting with spontaneous pneumothorax and investigate for other clinical manifestations of this syndrome. CONCLUSIONS: While Birt-Hogg-Dube is a rare syndrome, it is important to consider this diagnosis when evaluating a patient with cystic lung disease, in particular those who develop pneumothoraces. Reference #1: Menko, F. H., Van Steensel, M. A., Giraud, S., Friis-Hansen, L., Richard, S., Ungari, S., ... & European BHD Consortium. (2009). Birt-Hogg-Dubé syndrome: diagnosis and management. The lancet oncology, 10(12), 1199-1206 DISCLOSURES: Speaker/Speaker's Bureau relationship with Boehringer-Ingelheim Pharmaceuticals Please note: $5001 - $20000 Added 04/07/2020 by Jaime Betancourt, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with Vapotherm, Inc Please note: $5001 - $20000 Added 04/07/2020 by Jaime Betancourt, source=Web Response, value=Honoraria No relevant relationships by Kevin Eng, source=Web Response No relevant relationships by Laura Glassman, source=Web Response