Birt-Hogg-Dub Syndrome
Birt-Hogg-Dub Syndrome Causes
The cause of BHDS is not known, but it is inherited in an autosomal dominant pattern. Several reports suggest BHDS may be the result of the inactivation of a tumor suppressor gene, which results in the cutaneous hamartomas associated with internal neoplasia. Recently, the BHDS gene locus has been traced to chromosome 17p11.2. The FLCN gene delivers instructions for making a protein called folliculin. The normal function of this protein is not known, but researchers believe that it may serve as a tumor suppressor. Tumor suppressors hinder cells from growing and dividing too rapidly or in an uncontrolled way. Mutations in the FLCN gene may interfere with the ability of folliculin to stop cell growth and division, leading to the formation of noncancerous and cancerous tumors. Researchers have not determined how FLCN mutations increase the chances of lung abnormalities, such as a pneumothorax.
Birt-Hogg-Dub Syndrome Definition
Birt-Hogg-Dub syndrome is a rare disorder that affects the skin and lungs and heightens the risk of certain types of tumors. The condition is characterized by multiple noncancerous (or benign) skin tumors, particularly on the face, neck, and upper chest of the person. These growths typically first appear during a person's twenties or thirties and become larger in size and more numerous over time. Affected individuals also have a higher chance of developing cysts in their lungs and an abnormal accumulation of air in the chest cavity (pneumothorax) that may lead to the collapse of a lung. Additionally, people with Birt-Hogg-Dub? syndrome have a greater risk of developing cancerous or noncancerous kidney tumors and possibly tumors in other organs and tissues.
Birt-Hogg-Dub Syndrome Symptoms and Signs
Birt-Hogg-Dube is asymptomatic, but small, papular skin lesions develop gradually over the scalp, face, neck, and upper trunk of the patient. Papules are distributed predominantly over the scalp, face, oral cavity , neck, and upper trunk. These papules are multiple in number, small (ragning from 2-4 mm), white?to?flesh-colored, smooth, and dome-shaped. Acrochordons are papules that are small, soft, furrowed, 1- to 2-mm in size that may occur on the eyelids, neck, axilla, and upper half of the trunk. Oral mucosal polyps, collagenomas, angiolipomas, and deforming lipomas also have been reported in connection with BHDS.
Birt-Hogg-Dub Syndrome Treatment
Treatment for patients affected with Birt-Hogg-Dube syndrome includes screening and management of pulmonary, renal, and gastrointestinal findings. Additionally, skin findings may be treated for cosmetic purposes. Some options for removal of these lesions include electrocautery, dermabrasion, and resurfacing with the carbon dioxide or Er:YAG lasers.