A78-20 An Interesting Case of Birt-Hogg-Dubé Syndrome Presenting With Spontaneous Pneumothorax

Abstract Introduction Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominant genodermatosis characterized by pulmonary cysts with a predisposition to spontaneous pneumothorax, cutaneous fibrofolliculomas, and an increased risk of renal tumors. While BHD often presents in mid-adulthood, presentation may occur later in life, particularly in patients without a clear family history or prior overt respiratory symptoms. Case Description We present the case of a man in his 70s with no significant pulmonary history who developed a left-sided spontaneous pneumothorax shortly after a minor surgical procedure identified on chest x-ray. Chest computed tomography revealed multiple bilateral pulmonary cysts and subpleural bullae Image 1. Physical examination demonstrated characteristic white papular skin lesions on the face. A comprehensive workup for autoimmune and infectious causes was negative. Genetic testing identified a pathogenic variant in the FLCN gene, confirming the diagnosis of BHD. Renal imaging showed no evidence of renal tumors at the time of diagnosis. Conclusion This case underscores the importance of considering BHD in the differential diagnosis of spontaneous pneumothorax and cystic lung disease, even in older patients. Early recognition facilitates appropriate renal cancer surveillance and genetic counseling for at-risk family members. Clinicians should maintain a high index of suspicion in patients with pulmonary cysts and cutaneous findings, regardless of age or family history. This abstract is funded by: None