Immunohistochemical study of epidermal Langerhans cells and dermal dendritic cells in benign and malignant skin lesions characterized by a dermal lymphoid infiltrate consisting either of B-cells or T-cells

Abstract

Skin biopsies from 43 patients with a rather dense dermal lymphoid infiltrate of either inflammatory or neoplastic nature have been investigated. We studied the number, distribution and immunophenotype of epidermal Langerhans cells and dermal dendritic cells. As previously reported, differences in epidermal Langerhans cell and dermal dendritic cell numbers between skin biopsies with a B-cell infiltrate and skin biopsies with a T-cell infiltrate were found, dendritic cells being more numerous in the latter. The main finding of this study was an uneven distribution of epidermal Langerhans cells and dermal dendritic cells in skin biopsies with a T-cell infiltrate: in skin lesions with an inflammatory lymphoid infiltrate, small clusters of epidermal and dermal dendritic cells admixed with T-lymphocytes (predominantly T-helper/inducer cells) and small blood vessels were present at areas of exocytosis. In skin lesions with a neoplastic lymphoid infiltrate larger, more loosely arranged aggregates of dendritic cells and T-cells were seen. These cell aggregations composed of activated (inflammatory or neoplastic) T-cells and dendritic cells may represent the cutaneous homologue of the secondary T-nodule in the lymph node. Both types of cell aggregates may correspond to the dendritic cell-T cell clusters observed in in vitro induced immune responses.

Study of the reactive dendritic cells in small B-cell lymphoproliferations of the skin

“…Others suggested that the abundance of CD1a + cells might be useful in the differentiation between CTCL and pseudo-CTCL [9]. Drijkoningen et al [3] quantified DC (LC and DDC) and their distributions in benign and malignant cutaneous lymphoproliferations. They found that DC were more numerous in T-cell infiltrates than B-cell infiltrates.…”

Papular Acrodermatitis of Childhood (Gianotti‐Crosti Disease)

“…Drijkonigen et al (17) analyzed their own results and data from the literature and found that inflammatory infiltrates consisting of dendritic cells and T cells in the skin and around the small vessels are similar to the secondary T nodules of the paracortex of the reactive lymph nodes. The latter can be correlated with the dendritic cel!-T cell clusters of the primary immune response observed in vitro (17). This delayed type of T cell immune response can be induced by a number of chemical and physical effects or pathogens.…”

Gianotti-Crosti syndrome

“…77 The papillary dermis features an intense lymphocytic perivascular infiltrate consisting of T cells and dendritic cells, as is seen in many inflammatory dermatoses. 78 Most of the lymphocytes are CD4 1 and CD8 1 T cells; cytotoxic T cells seem to be a special feature of EBVinduced GCS. 42 In the nonvesicular form, the epidermis may have modest acanthosis and focal parakeratosis and spongiosis.…”