Relationship of the degree and type of intraductal component with other morphologic findings in breast cancer.

The presence of mammary lobules around overt cancer and the amount and the type of intraductal tumor component (solid, comedo, cribrous, comedo-cribrous, papillary) were defined in 493 consecutive cases of infiltrating human breast cancer to analyze the association of these parameters with other morphologic parameters, such as productive fibrosis, lymphoid infiltrate and nuclear grade. Data showed a significant inverse relationship between degree of intraductal component and productive fibrosis (p less than 0.01) and direct relationships between a) presence of lobules and degree of intraductal component (p less than 0.02) and b) intraductal component of comedo type and lymphoid infiltrate (p less than 0.02). In addition, marked though not significant associations were observed between a) absence of lobules and intraductal component of papillary type (p less than 0.10) and b) nuclear grade 1 and intraductal component of the comedo type (p less than 0.10). Data suggest that cancers with a high degree of introductal component could have a lobular origin and papillary cancer could have a ductal origin. The other relationships observed might be useful in the subclassification of NOS (not otherwise specified) breast cancer.