Sequential effects of photodynamic treatment of basal cell carcinoma.

Background: Photodynamic therapy (PDT) of superficial basal cell carcinoma (SBCC) acts as a biological response modifier or killing target cells, but sequential biological effects have not been reported in depth in humans.

Methods: In 15 patients with SBCC treated with aminolevulinic acid (ALA)-PDT, inflammatory infiltrate, apoptosis phenomena and tumor-derived molecules were investigated on biopsies at baseline, and after 15 min and 4, 24, 48 and 72 h, by immunohistochemistry and ultrastructure.

Results: Early apoptosis of keratinocytes was already observed at 15 min, while late apoptotic markers were maximally found at 24 h.

Fibrosis in regressing melanoma versus nonfibrosis in halo nevus upon melanocyte disappearance: could it be related to a different cytokine microenvironment?

Background: It is not clear why melanocyte disappearance occurs without fibrotic evolution in halo nevus and with fibrotic evolution in regressing melanoma.

Methods: Six halo nevi, seven regressing primary melanomas, and seven primary melanoma (PM) without regression were studied using immunohistochemistry for the phenotype of inflammatory infiltrate and the expression of cytokines involved in fibrogenesis or macrophage regulation. Melanocytes were also evaluated using electron microscopy.

New insights into the pathogenesis of vitiligo: imbalance of epidermal cytokines at sites of lesions.

Vitiligo is a skin disease that is caused by selective destruction of melanocytes and is characterized by white spots. Melanocytes and keratinocytes seem to exhibit a functional close relationship, mediated at least in part by keratinocyte-derived cytokines, which seem important for survival and activity of melanocytic cells. We wanted to investigate the hypothesis that in vitiligo the expression of epidermal cytokines may be modified compared with normal skin.