Spontaneous Pneumothorax Diagnosed As Birt-Hogg-Dubé Syndrome: A Report of a Rare Case.

The aim of this case report is to highlight the rare occurrence of spontaneous pneumothorax as the initial presentation of Birt-Hogg-Dubé (BHD) syndrome, its diagnostic modalities, manifestations, and treatment approach. A spontaneous pneumothorax occurs when air enters the pleural space in the absence of trauma. Primary spontaneous pneumothorax, which occurs in the absence of any underlying cause, is generally due to the rupture of subpleural emphysematous blebs. Mutations in a tumour-suppressor gene (FLCN gene) result in BHD syndrome, an autosomal dominant condition, which is usually characterized by the formation of pulmonary cysts, skin fibrofolliculomas, and renal tumours. We report a case of a 38-year-old male, a non-smoker, who presented with complaints of right-sided chest pain, shortness of breath, and dry cough. Clinical examination showed reduced chest movements, hyper-resonance notes, and reduced breath sound on the right hemithorax. Chest X-ray showed pneumothorax on the right side, and high-resolution computed tomography (HRCT) of the thorax showed multiple thin-walled cysts in bilateral lungs. Whole genomic sequencing identified mutations in the FLCN gene, confirming the diagnosis of BHD syndrome. Management included intercostal drainage tube insertion for pneumothorax, high-flow oxygen therapy, and symptomatic care. Post-discharge recommendations included pneumococcal and annual influenza vaccinations, pulmonary function monitoring, renal tumour screening, and genetic counselling for family members. This case highlights that not all cases of BHD syndrome present with the classical triad of pulmonary, skin, and kidney abnormalities. Some cases may manifest solely with pulmonary features, such as spontaneous pneumothorax. Pulmonary cyst rupture is a hallmark of BHD syndrome and often leads to recurrent pneumothorax. Early diagnosis and genetic testing are critical for optimal management and prognosis. This case emphasizes the variability in BHD syndrome presentation and underscores the importance of comprehensive evaluation, genetic testing, and long-term surveillance to manage potential complications. Genetic counselling of family members is essential to identify at-risk individuals and ensure timely interventions.