Lectin‐binding sites in clear cell acanthoma

Abstract

Lectin‐binding sites in clear cell acanthoma (CCA) were studied using an avidin‐biotin complex (ABC) with 9 lectins. Formaldehyde‐fixed, paraffin‐embedded sections of 7 CCA lesions were employed. Positive stainings, similar to those seen in normal epidermis, were observed on the cell surface in CCA with Ricinus communis agglutinin I (RCA‐I), Ricinus communis agglutinin II (RCA‐II), and wheat germ agglutinin (WGA). Reduced reactivities were observed with Concanavalin A (ConA) and peanut agglutinin (PNA) in CCA. In some areas of CCA lesions, faint stainings were seen with Ulex europaeus agglutinin I (UEA‐I). Capability of staining with soybean agglutinin (SBA) was completely lost in the lesions. With Bandeiraea simplicifolia agglutinin II (BSA‐II), cytoplasmic stain was seen in a part of upper and spinous layers in CCA lesions. Dolichos biflorus agglutinin (DBA) did not bind to either CCA or normal epidermis. These results indicate that the lectin‐binding sites of proliferating cells of CCA resemble those of epidermal keratinocytes and suggest that CCA is a tumor of epidermal origin.