Poikiloderma of Civatte: a histopathological and ultrastructural study

BACKGROUND: Poikiloderma of the face and neck (Civatte) has not been studied in depth for decades, especially as far as the histopathology is concerned. MATERIAL AND METHODS: We studied 50 consecutive patients with poikiloderma of Civatte (PC). Their evaluation included: history, physical examination, lesional skin biopsy and histological examination of sections stained with hematoxylin-eosin, PAS, Fontana-Masson, acid orcein Giemsa for elastic fibers and toluidine blue for mast cells. In 10 randomly selected subjects, a second skin biopsy was performed and specimens were examined under the electron microscope. RESULTS: There were 34 females (68%) and 16 males. The mean age at diagnosis was 47.8 years for females and 61.7 years for males. Histological examination revealed an atrophic (62%), flattened (84%) epidermis with hyperkeratosis (92%) and occasional follicular plugging (34%). In some cases, mild hydropic degeneration of the basal cell layer was evident (46%). Melanin was irregularly distributed in the lower epidermis (94%), and melanophages were often present in the dermis (92%). The most prominent and constant feature (100%) was solar elastosis of the papillary dermis. The blood vessels were almost invariably dilated (96%) with a mild perivascular lymphohistiocytic infiltrate (78%), sometimes with plasmacytes (56%). At the ultrastructural level, the epidermis showed only minor changes. The dermoepidermal junction was intact. The most constant findings were swelling and disruption of the collagen fibers as well as focal degeneration of the collagen bundles. Occasionally, several vacuolar spaces were found just under the basal lamina. Melanin-laden macrophages scattered in the dermis were also detected. CONCLUSIONS: PC shows distinct histological and ultrastructural features, supporting the theory that it represents a separate entity. The histology of PC is characteristic but not pathognomonic. On this basis, the differential diagnosis from Riehl's melanosis, poikiloderma atrophicans et vasculare and other acquired poikilodermas can be made. Ultrastructural findings were consistent with the histological findings. Changes of the dermal connective tissue (solar elastosis) predominated, providing morphological evidence for the role of ultraviolet radiation in the pathogenesis of PC.