Isoantigens A, B, H in normal skin and tumors of the epidermal appendages.

Isoantigens A, B, H(O) in biopsy specimens of 26 normal skin and in 35 adnexal tumors were studied by the red cell adherence (RCA) test of Davidsohn. Isoantigens were detected in the stratum corneum, stratum granulosum, stratum spinosum, acrosyringium, keratogenous zone of hair follicle, eccrine duct, and eccrine gland. The apocrine gland and duct consistently had negative test results for isoantigens. Seventy percent of all tumors tested contained isoantigens and included syringoma, hidrocystoma, syringocystadenoma papilliferum, spiradenoma, eccrine poroma, dermal duct tumor, clear cell hidradenoma, and cylindroma. We interpreted the presence of isoantigens in adnexal tumors as being evidence of immunologic maturity with differentiation toward eccrine structures. The RCA test is a new, sensitive, immunologic technique that can complement enzyme histochemical stains and electron microscopy in the study of the histogenesis of adnexal skin tumors.