Evaluation of angiogenesis in normal and lichen planus skin by CD34 protein immunohistochemistry: preliminary findings.

Angiogenesis is a critical component of both neoplastic and chronic inflammatory disorders, but whether angiogenesis also occurs in inflammatory skin diseases (such as lichen planus) has yet to be established. This study tests the hypothesis that the development of cutaneous lichen planus is associated with alterations of dermal vascularization (microvessel density, MVD). Thirty cases of cutaneous lichen planus and 40 cases of normal skin were studied. Dermal microvessels were immunostained for CD34 and counted in 10 areas with the highest numbers of microvessels; the mean value represented the final MVD. Compared with normal skin, dermal microvessel density was increased in cutaneous lichen planus [mean, 2.50 (SEM, 0.09) versus 1.39 (SEM, 0.12)]. The microvessel number was higher in the dermal inflammatory infiltrate (intralichenoid infiltrate) and at dermoepidermal junction (below Max-Josef space) compared with adventitial dermis [mean, 2.50 (SEM, 0.09) versus 1.6 (SEM, 0.10)]. The higher MVD values in cutaneous lichen planus suggest a possible link between angiogenesis, and development of these cutaneous lesions. These results provide a morphological evidence of potent angiogenic activity in cutaneous lichen planus, indicating that the local microvasculature may undergo an intense process of inflammation-dependent angiogenesis.