The Tuberous Sclerosis Complex

Abstract

Tuberous sclerosis complex (TSC) is the now preferred name for the autosomal dominant condition also known as tuberous sclerosis (OMIM # 191100). The addition of the term complex (first introduced in 1942 by the pathologist Moolten) emphasizes the multisystem involvement and variable expression of the disease, which “may affect any human organ with well-circumscribed, benign, non-invasive lesions known as hamartias and hamartomas” (Gomez 1999). The skin, brain, retina, heart, kidney, lung and liver are the organs most often involved, usually with the lesions called hamartomas (i.e., well-circumscribed groups of disorganized/dysplastic cells that, in addition, have a propensity to multiply excessively, thus growing as benign tumours that may or may not cause symptoms e.g., cardiac rhabdomyomas and renal angiomyolipomas) (Wilson et al. 2005) or with the other characteristic TSC lesion, the hamartias (i.e., well-circumscribed, misaligned or misarranged groups of dysplastic cells that nevertheless are appropriate for the organ or tissue involved and do not multiply or grow more rapidly than the normal cells of the affected organ e.g., hypomelanotic maculae in the skin, depigmented spots in the retina and cortical tubers in the brain).