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Biomedical subjects

Y Gauthier

Publications and source records attributed to Y Gauthier.

At least 73 records · Page 4Linked to original sources

[Hypomelanosis of the skin and malignant melanoma (author's transl)].

8 patients suffering from malignant melanoma have been found to have various degrees of hypomelanoses of the skin. Depigmentation of the skin and/or hair associated with malignant melanoma may take several forms. Schematically six clinical types are described: - vitiligo-like hypomelanoses distant from cutaneous tumors; - vitiligo-like depigmentation associated with uveitis (incomplete Vogt-Koyanagi); - hypomelanoses in the primary tumor and/or its metastases; - "halo melanoma" in which the hypomelanoses encircles the primary tumor and/or its metastases; - halo nevi around preexisting benign nevocellular nevi; - "non-specific depigmentary phenomen" distant from the primary tumor or its metastases. Histological and ultrastructural studies of the depigmented skin show an absence of melanocytes. The association of hypomelanoses of the skin with malignant melanoma is probably not coincidental. Various hypothesis are discussed as well as the prognostic significance of such an association.

Adult↗

Ultrastructure of halo nevi.

An ultrastructural study was conducted on eight halo nevi. Some of them were of recent onset. Others had an evolution of several months. The distribution of the population of the dendritic cells in the depigmented epidermis of the halo was more polymorphous at the early stage when few melanocytes with abundant cytofilaments and some Langerhans cells were seen. At an advanced clinical stage, only Langerhans cells were present in the basal layer. In the dermis abnormal nerves as in vitiligo were observed. The inflammatory infiltrate does not seem to appear at the early stage of involution of the nevus. At the advanced clinical stage, small mononuclear cells were also noticed among the inflammatory cells (lymphocyte-like cells, macrophages, mast cells). It is suggested that an initial stage of inhibition of both the melanocytes and the nevus cells may be responsible for the development of the depigmented halo. This stage precedes the appearance of a dermal lymphomacrophagic infiltrate that leads to the destruction of the nevus.

Adolescent↗