The identification of mononuclear cells extracted from cutaneous tumours (basal cell carcinoma, squamous cell carcinoma and superficial, spreading melanoma) has been investigated. The relative numbers of T cells and B cells have been determined using the E-rosette test and the EAC-rosette test. The results have been compared to those of delayed hypersensitivity type reactions. Different cell distribution patterns (E/EAC ratio) have been found in the infiltrates according to the type of tumour. An immunocytochemical technique has been developed for the identification in situ of immunoglobulin-producing cells in the inflammatory infiltrates. In each case the class of immunoglobulin (IgM, IgG or IgA) has been identified and the relative frequency of Ig-producing cells has been determined. The results indicate humoral and cellular immune responses with variations attributable to the type of tumour. In weakly malignant tumours, the infiltrate is characterized by an elevated number of T lymphocytes and numerous plasma cells which secrete all classes of Ig; in highly malignant tumours it is characterized by a reduced number of both T lymphocytes (E rosette) and plasma cells which do not secrete all classes of Ig.

An immunocytochemical technique has been developed for the identification in situ of immunoglobulin-producing cells in tissues fixed in Bouin's solution and embedded in paraffin. Technical details are discussed as well as the application of the technique to the study of plasma cells in the inflammatory infiltrate around cutaneous tumors. Preliminary results have been obtained with basal cell epitheliomas, squamous cell carcinomas, and malignant melanomas. IgA-producing cells were present in all tumors. IgG-producing cells were present in variable frequency, depending on the type of tumor, and IgM-producing cells were found only in basal cell epitheliomas and squamous cell carcinomas.

No abstract

No abstract