Histologic changes in incipient carcinoma of the breast

The histopathologic grades, degrees of nuclear differentiation and lympho-cytic infiltrates in 38 intraductal mammary carcinomas are compared with these features of 254 ordinary invasive carcinomas and 35 cases with special types of carcinoma, all clinically localized, Stage A. Significantly, more well-differentiated carcinomas with differentiated nuclei occurred in the intraductal group, and more undifferentiated carcinomas with poorly differentiated nuclei were found among the invasive tumors. These discrepancies are believed to reflect enhanced invasion by less differentiated mammary carcinoma cells.