Quantitative histopathological variables in in situ and invasive ductal and lobular carcinomas of the breast

This study was carried out to compare quantitative histopathological estimates obtained in normal breast epithelium (N = 15), lobular carcinoma in situ (N = 29), ductal carcinoma in situ (N = 24), invasive lobular carcinoma (N = 39), and invasive ductal carcinoma (N = 71) of the female breast. Using unbiased stereology, the three-dimensional mean nuclear size, v v(nuc), was estimated in routine histological sections, along with morphometric point-counting based estimates of the mean nuclear profile area, aH(nuc), and estimates of the nuclear density index, NI, the mitotic index, MI, and the nuclear volume fraction, Vv(nuc/tis). The vv(nuc), aH(nuc), and MI were, on average, larger in ductal than in lobular carcinomas (2p < or = 0.01), whereas the mean NI was smaller in ductal carcinomas (2p = 3.10(-4). Comparing estimates obtained in tumors of pure ductal carcinoma in situ (N = 11) with those obtained in tumors of pure lobular carcinoma in situ (N = 7), only the difference in mean NI reached statistical significance (2p = 0.001). Several significant differences were found between means of quantitative histopathological estimates obtained in normal breast epithelium, pure in situ lesions, and invasive carcinomas. Overlaps were, however, evident among the groups. There were no significant differences between means of the quantitative variables obtained in carcinoma in situ of the ductal and the lobular type with or without accompanying invasive carcinoma (2p > or = 0.22). A close correlation was found between estimates of vv(nuc) obtained in the in situ component and the invasive part of ductal carcinomas (r = 0.86, 2p = 2.10(-4). Previous studies have shown prognostic value of quantitative histopathological variables in breast carcinomas. The present study points to an additional value of the investigated variables in the diagnostic separation of normal breast epithelium, in situ lesions, and invasive carcinomas. The quantitative variables obtained in the situ lesions did not indicate whether an accompanying invasive tumor was present or not.