H, Peanut Lectin Receptor, and Carcinoembryonic Antigen Distribution in Keratoacanthomas, Squamous Dysplasias, and Carcinomas of Skin

The distribution of blood group antigen H(O), peanut lectin receptor (PNL‐R) (a precursor to the MN blood group antigens), and carcinoembryonic antigen (CEA) was examined in 15 squamous cell carcinomas, 30 keratoacanthomas, 17 squamous dysplasias, and 5 normal controls using immunoperoxidase techniques. All controls and 8 carcinomas, 10 keratoacanthomas, 14 dysplasias expressed H antigen. All controls and 9 carcinomas, 10 keratoacanthomas, 16 dysplasias expressed PNL‐R antigen. CEA was present in 15 carcinomas, in trace amounts in 3 keratoacanthomas, in 6 dysplasias, and in 0 controls. The staining for H antigen and PNL‐R in the carcinomas and dysplasias was disorganized, patchy, and less than that of normal epithelium, while staining in keratoacanthomas was uniform, with normal to increased intensity as compared to controls in 9 cases. CEA showed weak focal staining in 5 carcinomas, 8 dysplasias and 3 keratoacanthomas, and more intense and extensive cytoplasmic and membrane staining in 10 carcinomas and 5 dysplasias, and no cellular staining in 4 dysplasias and 7 keratoacanthomas. CEA was present in greatest amounts in the well‐differentiated carcinomas and focal in the less‐differentiated tumors. The well‐differentiated carcinomas had a greater percentage of cells staining for H antigen and PNL‐R. The pattern of staining for H, PNL‐R, and CEA appears to distinguish keratoacanthomas from carcinomas and squamous dysplasias, and may be a useful adjunct to diagnosis.