The intermediate filaments and prognostically oriented morphological classification in ductal breast carcinoma.

The expression of cytokeratins 7, 8, 14, 18, 19 and vimentin was examined in 100 cases of ductal invasive breast carcinomas. While the predominantly diffuse immunohistological positivity of simple epithelia cytokeratins 7 (in 93), 8 (in 100), 18 (in 100) and 19 (in 97) cases represents a constant feature of these tumors, cytokeratin 14 was detected in only 36 cases which were mostly of low grade and in a focal pattern. Vimentin positivity was found in 53 intermediate and high grade tumors and, again the pattern was also rarely diffuse. The ductal carcinomas can be grouped into four classes according to vimentin and cytokeratin 14 immunoreactivity. This grouping correlates well with tumor grade and with simple histological classification of ductal breast carcinoma, consisting of the low, intermediate and high malignancy categories, as proposed here. The types ofductal carcinomas can be sorted into prognostically different subgroups, according to ICD-O morphologic terminology and commonly adopted results of morphologic and prognostic studies.