Tip of the Iceberg: Forme Fruste Tuberous Sclerosis in a Child

Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder characterized by dermatologic manifestations and growth of multiple benign tumors often involving the brain, skin, kidneys, heart, lungs, and liver. It exhibits wide phenotypic variation, ranging from the most severe cases with intellectual disability and intractable epilepsy to the mildest, clinically silent forms of the disease. The incidence of TSC is reported to be 1/6000; however, this does not account for those with milder forms of the disease, of which forme fruste is the mildest. Forme fruste is a French term for a “crude or unfinished form.” In medicine, it refers to an atypical or attenuated manifestation of a clinical condition and implies an incomplete, partial, or an aborted disease state. Here, we describe a rare case of forme fruste TSC incidentally diagnosed in an otherwise healthy child, highlighting the implications of the diagnosis for treatment and screening in similarly affected pediatric patients.