Determination of DNA ploidy and ABH antigen reactivity in both frozen and formalin-fixed bladder tumor tissue

In a prospective series of patients with transitional-cell bladder carcinomas, DNA ploidy and ABH antigen reactivity were determined in both frozen tissue and formalin-fixed paraffin blocks. ABH antigen measurement in frozen tissue was hampered by methodological problems, especially insufficient morphology, which made quantification difficult. In only 38/55 (69%) cases was the same ABH reactivity found. The knowledge of secretor status was not helpful in the interpretation of these results. In 53/59 (90%) cases the same DNA ploidy was achieved, resulting in good correlation between flow cytometric DNA measurements in formalin-fixed and frozen tissue. The deviations occurred mainly in cases exhibiting a tetraploid DNA profile. DNA assessments using image cytometry on imprints of fresh tissue was a rapid and reliable method in our hands, with identical results being obtained in 32/36 (89%) cases.