Aneuploidy in chronic actinic dermatitis.

DNA content and cell cycle distributions in paraffin-embedded blocks of 19 skin biopsy specimens from 17 patients with chronic actinic dermatitis (CAD) [8 patients showed typical actinic reticuloid (AR)] were estimated by DNA cytometry. Sixty-three percent (12/19) of the skin specimens showed aneuploidy. In the 4 cases with the highest DNA indices (DI), ranging from 1.65 to 1.88 (mean: 1.84), the proportions of cells in S and G2/M phases were increased, ranging from 15-48% (mean: 20%) and from 64-76% (mean: 70.5%), respectively. In 8 cases with DI ranging from 1.15-1.75 (mean: 1.5), the proportion of cells in S-phase was also increased, ranging from 30-90% (mean: 81.1%). Histologically, it seems likely that the relatively high frequency of aneuploidy, DI, and proportions of cells in the S and/or G2/M phases were not proportional to epidermal or vascular endothelial hyperplasia, but they might be related to dermal lymphoid infiltration.