Although the overall incidence of breast cancer in African-American women is lower than in white women, African-American women younger than 50 years old have a higher incidence of breast cancer than white women. African-American women with breast cancer have a poorer survival rate than white women and are more likely to die of breast cancer in almost every age group. To explain this disparity, we studied a substantial body of literature that reported a biologic difference in the tumors found in African-American and white women. Specifically, more aggressive histopathologic patterns have been described among African-American patients with breast cancer when compared with white women. In addition, there are data that support an ethnicity-related variation in the expression of breast tumor hormonal markers. The objective of this study was to critically evaluate the existing published data on the histologic features of breast cancer to determine whether breast cancer in African-American women is a histologically more aggressive disease than in white women. We conclude that the aggressive tumor histology reported in African-American women has not been analyzed carefully with respect to the age of the patient at the time of diagnosis and the stage of disease at presentation. Furthermore, there is a need for central pathology review using accepted, published criteria for diagnosis of uncommon and controversial histologic subtypes of breast cancer.