Introduction

Tuberous sclerosis complex (TSC) is a dominantly inherited disorder, which affects the brain, skin, heart, lungs, kidneys, and other organs (Roach et al., 1998). Many of the clinical manifestations of TSC result from hamartomas of these organs, and abnormal neuronal migration plays a major additional role in neurologic dysfunction (Sparagana & Roach, 2000). Because of its striking variability of clinical expression and severity, the diagnosis of TSC can be difficult in individuals with subtle findings. The clinical diagnostic criteria were recently revised (Table 6.1). Population-based studies suggest a prevalence of 1 per 6000 to 9000 individuals (Osborne et al., 1991).

Clinical manifestations

Skin lesions

The cutaneous lesions of TSC include hypomelanotic macules (‘ash leaf spots’), the shagreen patch, facial angiofibromas (‘adenoma sebaceum’), and ungual fibromas (Roach & Delgado, 1995). Hypomelanotic macules are found in over 90% of patients (Fig. 6.1); poliosis of the scalp hair or eyelids occur less often. The lesions are usually present at birth but can be difficult to see in the newborn without an ultraviolet light. Hypomelanotic macules are not specific for TSC: one or two of these lesions sometimes occur in normal individuals (Vanderhooft et al., 1996).

Facial angiofibromas contain both vascular and connective tissue elements. These lesions are found in about three-fourths of patients and typically become apparent during the preschool years as small red papules on the malar region (Roach & Delgado, 1995). They gradually become larger and more numerous, sometimes extending down the nasolabial folds or onto the chin (Fig. 6.1).