Progressive Hyperpigmentation and Generalized Lentiginosis without Associated Systemic Symptoms: a Rare Hereditary Pigmentation Disorder in South-East Germany
Livia Zanardo, Wilhelm Stolz, Gerd Schmitz, Wolfgang Kaminski, Miikka Vikkula, Michael Landthaler, Thomas Vogt
Familial progressive hyperpigmentation is rarely described in the literature. We report on five patients from three different families presenting with a peculiar progressive pigmentary disorder. The patients show a progressive diffuse, partly blotchy, hyperpigmentation, intermixed with scattered small hypopigmented macules, a few large hypopigmented areas, occasional café-au-lait spots and, most remarkably, a generalized lentiginosis. Histology revealed different degrees of basal layer hyperpigmentation and pigment incontinence, also in the spots appearing hypopigmented. Ultrastructural analysis showed a normal mode of Caucasian-like melanogenesis with varying content of regular melanosome complexes within the keratinocytes. All families are clustered in a small area around the town of Teublitz in south-east Germany with about 20,000 inhabitants, suggesting a genetic founder effect. Pedigree analysis is compatible with an autosomal dominant mode of inheritance with variable penetrance. Only a few similar, but not identical, cases have been reported in the past. This cluster of cases may therefore represent a rare and perhaps novel variant of a familial progressive disorder of hyperpigmentation.