IMPORTANCE OF BROAD DIFFERENTIAL FOR SPONTANEOUS PNEUMOTHORAX: BIRT-HOGG-DUBE SYNDROME

SESSION TITLE: Pulmonary Manifestations of Systemic Disease Case Report Posters 13 SESSION TYPE: Case Report Posters PRESENTED ON: 10/10/2023 09:40 am - 10:25 am INTRODUCTION: Increased use of high-resolution CT scans and advances in genetic testing has led to increase in diagnosis of cystic lung diseases. Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominant disorder characterized by benign skin lesions in the head and neck, pulmonary cysts, and increased risk of renal cancer. In this report, we describe a patient who presented with her first spontaneous pneumothorax that led to the detection of a renal cancer. This case highlights the necessity of obtaining high-resolution CT scans in the work up of primary pneumothoraces. CASE PRESENTATION: 54 year old female without pertinent pulmonary PMHx presented with spontaneous pneumothorax following a transatlantic flight. Initially diagnosed on CXR, CT Chest confirmed diagnosis and also showed multiple bilateral pleural blebs and a left adrenal mass. She was referred to cardiothoracic surgery for definitive surgical management. The differential diagnosis considered included lymphangioleiomyomatosis (LAM), BHD syndrome, lymphocytic interstitial pneumonia (LIP) and amyloidosis. Further workup was sent including SPEP/UPEP, alpha-1-antitrypsin, ANA, RF, SSA/SSB, tuberous sclerosis gene panel, FLCN, VEGFD. Her workup was significant for a positive FLCN gene with pathogenic variant consistent with BHD syndrome. Abdominal CT showed an 8 cm left adrenal mass, multiple bilateral renal masses consistent with renal cell carcinoma and a retroperitoneal mass consistent with pathologic adenopathy. The biopsy of the adrenal mass was inconclusive but showed epithelioid malignancy. She has been referred to the NIH for further management. DISCUSSION: BHD has an autosomal dominant inheritance pattern with deletion mutation in the folliculin (FLCN) gene. The clinical presentation may be variable, but there should be a high index of suspicion in those who present with fibrofolliculomas, renal cysts or bilateral renal carcinoma, and personal or family history of pneumothorax. It most commonly diagnosed through incidental findings on CT or during a workup of a spontaneous pneumothorax. The management is dependent on disease penetrance and clinical manifestation. The approach to treatment of a pneumothorax would be the same as with any secondary spontaneous pneumothorax. Early and frequent screening for renal malignancy is recommended, as majority of deaths in BHD are due to metastatic clear cell carcinoma tumors. Genetic counseling should be available to all first-degree relatives and carriers. CONCLUSIONS: Although Birt-Hogg-Dubé syndrome remains a rare disease, early diagnosis is essential given its high association with malignancy. For the pulmonologist, thorough history taking and knowledge of the disease and its different organ manifestations is vital to an early diagnosis to help prevent further morbidity and mortality from renal malignancies. REFERENCE #1: Menko FH, van Steensel MA, Giraud S, et al. Birt-Hogg-Dubé syndrome: diagnosis and management. Lancet Oncol 2009; 10:1199 REFERENCE #2: Daccord C, Good JM, Morren MA, Bonny O, Hohl D, Lazor R. Birt-Hogg-Dubé syndrome. Eur Respir Rev. 2020 Sep 17;29(157):200042. REFERENCE #3: Gupta N, Sunwoo BY, Kotloff RM. Birt-Hogg-Dubé Syndrome. Clin Chest Med. 2016 Sep;37(3):475-86. doi: 10.1016/j.ccm.2016.04.010 DISCLOSURES: No relevant relationships by Monazza Chaudhry No relevant relationships by Garth Garrison No disclosure on file for Syed Moin Hassan No relevant relationships by Sienna Searles