Nucleolar grading of breast cancer. Comparative studies on frequency and localization of nucleoli and histology, stage, hormonal receptor status and lectin histochemistry.

The localization and number of nucleoli of tumour nuclei were examined after conventional histological typing of breast carcinomas (WHO classification), staging, biochemical receptor status, and lectin binding site histochemistry. With increasing histological atypia and grade of malignancy, the frequency of nucleoli increased significantly and their location shifted from the center to the nuclear periphery. These changes correlated with an increase in indices of mitosis and cell loss. The nucleolar size correlated with the increase in the grade of malignancy. Hormone receptor and lectin binding site positive carcinomas were characterized by a low nucleolar frequency and by small nucleoli in central position, whereas carcinomas with high grades of malignancy and negative hormone receptor and lectin binding site status showed large, often multiple nucleoli in eccentrical position at a high frequency. The studies have demonstrated that nucleolar status is an easily practicable histological/cytological method for use in the assessment of prognosis of carcinomas of the breast.