Abstract Introduction Birt-Hogg-Dubé (BHD) syndrome is a rare autosomal dominant genetic disorder characterized by the triad of pulmonary cysts with recurrent spontaneous pneumothorax, cutaneous fibrofolliculomas, and an increased risk of renal neoplasms. The condition results from mutations in the FLCN gene located on chromosome 17p11.2, which encodes the folliculin protein involved in cellular growth regulation. Due to its variable presentation, BHD is frequently underdiagnosed, especially when presenting solely with pulmonary symptoms. Case Presentation A 34-year-old male presented with a sudden onset of right-sided chest pain and breathlessness. He denied constitutional symptoms or any prior history of systemic illnesses. Chest radiography revealed a right-sided pneumothorax, for which an intercostal chest drain was inserted. High-resolution computed tomography (HRCT) of the chest revealed bilateral multiple thin-walled cysts, predominantly located in the lower lobes, along with a large right pneumothorax and an intercostal drain in situ. The air leak persisted for three weeks. On physical examination, multiple small papular lesions were noted over the face and trunk. Skin biopsy of these lesions revealed fibrofolliculomas. Based on these findings, genetic testing for the FLCN gene was performed, which confirmed mutation consistent with Birt-Hogg-Dubé syndrome. Screening for renal tumours was negative. ICD was removed after Talc pleurodesis. His first-degree relatives were advised to undergo genetic testing. Discussion BHD syndrome manifests with pulmonary cysts and leads to recurrent pneumothorax as the common clinical presentation, subsequently leads to recognition of skin or renal involvement as in our case. The lung cysts in BHD are typically bilateral, thin-walled, and located in the lower and medial lung zones, distinguishing them from other cystic lung diseases. The FLCN gene mutation leads to aberrant activation of the mTOR pathway, contributing to cyst and tumour formation. Recognition of characteristic cutaneous lesions such as fibrofolliculomas, aids in clinical suspicion. Early diagnosis helps for genetic counselling, renal surveillance, and prevention of recurrent pneumothoraces through procedures like pleurodesis, as in our case. Conclusion This case underscores the importance of considering Birt-Hogg-Dubé syndrome in young adults presenting with spontaneous pneumothorax, particularly in the absence of infection. Evaluation of skin findings, family history, and targeted genetic testing can establish an early diagnosis, enabling lifelong surveillance for renal tumours and appropriate family screening. Recognition of extra-pulmonary manifestations remains crucial for timely management. This abstract is funded by: None
Nair et al. (Fri,) studied this question.