Bioclinical Study of Scalp Photoaging of a Population Male Over 65 Years Old.

Investigators can also hope to understand and to explain the inter-individual inequality of the aging of skin. They can hope to a better understanding of the biological mechanisms between photo-induced skin aging and photo-induced carcinogenesis. Investigators propose to study 40 male patients aged 65 and over in order to compare the state of aging of their scalp skin in the alopecic zone : not hairy photo-exposed (= ZH sun damage zone) versus occipital hair zone protected photo (= ZT control zone). Patients will be recruited in the dermatology department of the St-Etienne University Hospital who will benefit from the removal of a scalp tumour in the alopecic zone. This study aims to identify biological markers, by transcriptomic analysis, associated with aging of the scalp, by comparing for each patient the skin of the scalp exposed to the light ("ZH") to an unexposed witness skin ("ZT"). The study will include : * examinations to characterize components of the scalp: transcriptomic, proteomic and immunohistochemical analysis of skin biopsies, and a swab sampling will identify the cutaneous microflora of the scalp * noninvasive examinations, in vivo