Birt-Hogg-Dubé syndrome: a rare cause of cystic lung diseases.

Cystic lung diseases are characterised by multiple intrapulmonary cysts. They can be mimicked by other more common causes of focal parenchymal lucencies such as emphysema, bronchiectasis and honeycombing. The various conditions have differing managements and prognoses, thus correct evaluation is essential. Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant disorder, that is, a rare cause of cystic lung disease. It is seen in approximately 200 families worldwide. This case describes a 37-year-old woman who presented to a District General Hospital with symptoms of pleuritic chest pain and breathlessness. A CT pulmonary angiogram arranged to assess for pulmonary emboli excluded this but it demonstrated multiple intrapulmonary cysts. After further investigation and subsequent genetic testing this was confirmed to be BHD syndrome.