Analysis of tuberous sclerosis initially manifested as hypomelanotic macules in 12 infants

Abstract

Objective To investigate clinical characteristics of tuberous sclerosis (TSC) without nervous system abnormalities in infants. Methods Clinical manifestations of 12 infants with TSC were analyzed. Reflectance confocal microscopy (RCM) was performed in 5 of the 12 infants. Two patients underwent histopathological examination and electron microscopic examination. Results The age at first clinic visit for TSC ranged from 2 to 18 months (median, 8.6 months) among these patients. Before occurrence of nervous symptom, TSC mainly manifested as hypomelanotic macules, nodules in the subependymal layer or walls of lateral ventricles of the brain, cardiac rhabdomyoma and multiple renal cysts. RCM revealed intact dermal papillary rings with low reflectivity and obscure boundaries in 5 infants. Histopathological examination showed a local decrease in melanocytes and pigment granules in basal cells. Electron microscopic examination showed a normal number of melanin granules in the cytoplasm of melanocytes in the basal layer. Conclusions Before appearance of nervous system abnormalities, TSC mainly manifests as hypomelanotic macules in infants, and is easily confused with vitiligo in clinic. RCM examination may serve as a useful method to distinguish infant TSC from hypopigmented diseases. Key words: Tuberous sclerosis; Infant; Hypopigmentation; Vitiligo; Microscopy, confocal