BIOLOGICAL MALIGNANCY IN MUCINOUS CARCINOMA OF THE BREAST

—IMMUNOHISTOLOGICAL STUDY USING ANTI-SERA FOR PCNA—

Abstract

The biological malignant potentiality of 23 cases of mucinous carcinoma of the breast was studied. Each case was examined histopathologically and immunohistochemically using anti-PCNA antibody staining by the SAB method. Histologically, mucinous carcinoma was classified into 2 types, a pure type and a mixed type. 6 cases were classified as pure type, and 17 cases as mixed type characterized by mucinous and common components. Both types were sub-classified into 2 types: epithelial type and mucoid type. The labelling index of PCNA (PI) was higher in the mixed type than in the pure type, and in the epithelial type, PI was higher than in the mucoid type. Furthermore, PI of the non-mucinous part was about 2 times as high in the mixed type with scirrhous or solid tubular components as in the mucinous part. In conclusion, PI seems to be an important factor in deciding the prognosis of mucinous carcinoma, in addition to histology, infiltration and cellularity.