Tyrosinase-positive melanocyte distribution and induction of pigmentation in human piebald skin

New KIT mutations in patients with piebaldism

“…Nevertheless, the contraction of areas of poliosis or the appearance of new hyperpigmented lesions has been described in several cases [1,24]. Hayashibe et al [25] reported three cases of tyrosinase-positive melanocytes within the leukodermal lesions of piebaldism. Thus, repigmentation may occur in-patients with mild piebaldism phenotypes if the patients are carefully observed over a long period [1].…”

Repigmentation of the epidermis around the acrosyringium in piebald skin: an ultrastructural examination

“…In general, the leucoderma associated with piebaldism is stable throughout life, and there are few or no melanocytes in the regions of affected skin. However, the appearance of a new pigmented region in piebald skin has been reported in several cases 2,3 . This report describes evidence for repigmentation in piebald skin arising from a periacrosyringium region, based on ultrastructural observations.…”

Piebaldism: an autonomous autosomal dominant entity

“…It has been suggested that a defect in migration or differentiation of melanocytes is responsible (Comings & Odland 1966). Histological and ultrastructural abnormalities documented in both piebaldism and the Waardenburg syndrome are replacement of melanocytes and melanosomes by Langerhans cells (Comings & Odland 1966, Mosher & Fitzpatrick 1988, although Hayashibe & Mishima (1988) have found that regularly placed junction melanocytes may be cvident in the hypomelanotic skin. Histopathological studies in our patients confirmed the classical view; melanocytic activity was reduced in the areas of lesser pigmentation and absent in the totally depigmented areas.…”