Benign and malignant lymphocytic skin infiltrates: immunological patterns recognized by immunohistochemical staining with monoclonal antibodies.

Skin biopsies from 150 patients with cutaneous lymphoma, premalignant or "pseudolymphomatous" conditions and benign dermatoses were examined by immunoenzymatic staining of frozen sections with a panel of monoclonal antibodies against lymphocytes, macrophages and accessory cells. Two patterns of infiltration were identified. In one of these T cells associated with Langerhans cells and HLA-DR-positive macrophages of dendritic morphology, were seen. In the other B cell follicles were present in addition to the above type of infiltrate. The latter pattern was restricted to patch tests biopsies, cutaneous lymphocytomas, and malignant lymphomas of B-cell origin. It is concluded that lymphocytic skin infiltrates are divisible into different patterns of immunological reactions similar to those seen in lymphoid organs.