although up to 75% of cases may be caused by a spontaneous mutation. It is caused by mutations in the TSC1 gene on chromosome 9q34–encoding hamartin or the TSC2 gene on chromosome I6pl3–encoding tuberin. Patients present at birth and males and females are affected equally.
There are multiple skin findings in TS that may herald the diagnosis. The earliest findings are hypopigmented macules, found in 85% of patients. They may be in an ash-leaf shape or confetti pattern. Adenoma sebaceum, or angiofibromas, are present on the forehead, nose, and cheeks, and often present in childhood. Periungual angiofibromas called Koenen tumors tend to occur at puberty. Connective-tissue nevi called Shagreen plaques, or collagenomas, may be present, which is what our patient exhibits on his back. The lumbosacral region is the most common area for these to appear in the first decade of life.
TS can affect other organ systems in the body. Seizures, neuropsychiatric diseases, and mental deficiency are common. Cortical tumors, gliomas, and astrocytomas may develop in the brain. Congenital retinal hamartomas (phakomas) occur. Renal cysts and angiomyolipomas may occur in the kidneys. In the lungs, patients may develop lymphangiomyomatosis. Rhabdomyomas can occur in the heart in infancy and may regress spontaneously over time. Bony changes such as cysts and sclerosis may occur.
Treatment and monitoring of TS requires a multidisciplinary approach with neurology, pulmonology, cardiology, ophthalmology, orthopedics, and dermatology. Cosmetic treatment for angiofibromas includes CO2 laser, shaving, and dermabrasion. Topical rapamycin use has been described in the literature to improve the appearance of angiofibromas. Our patient has been using rapamycin 1% cream for more than 5 years and has had a substantial reduction in the size and number of angiofibromas.
This case and photo were submitted by Dr. Bilu Martin.
Dr. Bilu Martin is a board-certified dermatologist in private practice at Premier Dermatology, MD, in Aventura, Fla. More diagnostic cases are available at mdedge.com/dermatology. To submit a case for possible publication, send an email to dermnews@mdedge.com.
References:
Spitz J. Genodermatoses. A Clinical Guide to Genetic Skin Disorders. Philadelphia: Lippincott Williams & Wilkins, 2005.
James W et al. Andrews’ Diseases of the Skin. Philadelphia: Saunders, 2006.
Bolognia JL et al. Dermatology. London: Mosby Elsevier, 2008.