title: [Ulstrastructural study of various evolutive stages of pityriasis versicolor (author's transl)].
abstract: Small size, less numerous and sometimes clustered melanosomes, were seen within the melanocytes. The others organites alos showed  abnormalities: smaller mitochondria, abundant cytofilaments. Sometimes total degeneration of the melanocyte was seen. These alterations are variable, depending upon the evolutive stage of pityriasis versicolor: either hypopigmented undergoing treatment or not, or hyperpigmented. Reactions of several cellular types of the dermoepidermal unit could be observed: more numerous Langerhans cells located near the base of the epidermis, abundant nerve fibers in the superficial dermis and active fibroblasts of foetal type. A slight inflammatory infiltrate was present in some cases. It is suggested that a toxic effect of the fungus is responsible for the changes of the morphological aspects of the melanocyte.
mesh_terms: D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008544:Melanocytes / Q000648:ultrastructure; D010859:Pigmentation Disorders / Q000473:pathology; D014010:Tinea Versicolor / Q000473:pathology*
vernacular_title: Etude ultrastructurale de divers stades évolutifs de pityriasis versicolor.