Multifocal extracardiac rhabdomyomas: Extending the phenotype of Birt-Hogg-Dubé syndrome.

Birt-Hogg-Dube (BHD) syndrome is characterised by a triad of benign skin tumours, pulmonary cysts with an attendant risk of pneumothorax, and renal cancer. BHD is caused by heterozygous pathogenic variants in folliculin (FLCN), a tumour suppressor gene.