Histologic sections, imprint preparations and cell preparations by enzymatic lysis from thick sections of cases of breast carcinomas were used to study total nuclear DNA distribution by image cytometry. Histologic sections are a prerequisite to unequivocally identify tumour cells as well as whole connective tissue cells used as a standard. While imprint preparations and lysis preparations are quite comparable with respect to distributional features, only one of them suffices to recognize these features, especially peaks at higher ploidies. Using this two-method approach to breast carcinomas, it was possible to distinguish a distribution separate from previously recognized distributions: a distinct triploid peak appears for predominantly high grade malignant ductal carcinomas.
