Occurrence: de novo mutation or inheritance as an autosomal dominant trait with a high penetrance
Chromosome affected: 17p11.2
Gene affected: FLCN (also referred to as BHD), with deletion or duplication at exon 11
Product: folliculin
Onset: during adulthood
Skin lesions - multiple lesions covering the head, neck and upper thorax:
(1) fibrofolliculomas (most specific skin finding)
(2) angiofibromas (trichodiscomas)
(3) perifollicular fibromas
(4) acrochordons (skin tags)
(5) cutaneous collagenomas
Lungs:
(1) multiple, bilateral pulmonary cysts, which can rupture causing pneumothorax
Renal tumors - multiple and bilateral:
(1) oncocytomas
(2) chromophobe renal cell carcinoma
(3) oncoytoma-chromophobe renal cell carcinoma hybrid tumors
(4) papillary or clear cell renal cell carcinomas
Other lesions:
(1) oral papules
(2) parotid oncocytoma or parotid adenoma
