Progressive hyperpigmentation: case report with a clinical, histological, and ultrastructural investigation

A clinical, histological and ultrastructural study of a 38-year-old woman with generalized progressive hyperpigmentation is reported. Hyperpigmentation started in early infancy, progressed during childhood and has increased to a dark bronze-brown color with 'mottling' in the last 8 years. Histology and electron microscopy revealed epidermal hypermelanosis and 'negroid' distribution of melanosomes in keratinocytes. In our family, autosomal dominant phenotype transmission with 'variable expression' is suggested. The literature on the entity has been reviewed. This case is another rare example of familial progressive hyperpigmentation.