Abstract

The Beta-2-microglobulin is the part of light chain of human histocompatibility antigen (HLA). This protein can be observed in most of the human nucleated cells. Some of reports indicated that the Beta-2-microglobulin was lost completely or partially in the malignant or premalignant lesions. Observations on presence of Beta-2-microglobulin were made on 24 cases of malignant, premalignant and benign epithelial umors and 6 cases of normal or non-neoplastic epithelial lesions in the skin, using PAP method. The PAP method. 1) Normal epidermis and no-neoplastic cutaneous lesions (chronic non-specific dematitis, actinic change of skin with pseudoepitheliomatous hyperplasia) showed strong positive staining along the cutaneous epithelial cytoplasmic surface for Beta-2-microglobuin in all 6 cases. 2) Benign cutaneous tumors (keratoacanthoma, squamous cell papilloma and pigmented nevus) showed similar strong positive staining for Beta-2-microglobulin along the epithelial cell surface in 4 out 6 cases. Remaining 2 cases were out of 4 pigmented nevus, which showed weakly or pretty weakly staining. 3) Premalignant cutaneous lesions as solar keratosis showed generally weak positive staining along the epithelial cytoplasmic surface in all 4 cases. 4) Malignant cutaneous tumors (basal cell carcinoma, squamous cell carcinoma, Bowen's disease and malignant melanoma) showed mostly negative staining along the surface of epithelial cells for Beta-2-microglobulin, in 8 out of 14 cases. Remaining 6 cases showed slightly weak or patchy positive staining. As above observation, the presence of Beta-2-microglobulin in cutaneous epithelial lesions using PAP method could be indicated as one of good differential tool for histopathologic diagnosis in cutaneous malignant lesions.