For long, breast carcinoma has presented dilemma of varied shapes and sizes of tumour cells, their arrangements and products and heterogeneity of the tumour, for understanding the exact nature and types of the disease and the cells in the breast from which it originated precisely. Even now in wide geographic areas of the world, the usual practice is to diagnose breast carcinoma as lobular, intra-ductal, infiltrating lobular and infiltrating ductal, only rarely identifying the cell type, growth pattern. Known for intra epithelial infiltration, the breast carcinoma originating in any part of the breast ducts rapidly involves other segments, and undergoes rapid up and down regulations of the cells, hence, practice of final diagnosis of the breast carcinoma as lobular and ducal has little significance and is obsolete now. Cancer Care having entered Evidence Based era, cellular origin and molecular processes involved in the origin and evolution of the breast cancer had been focus of recent studies. This book presents histopathological classification of breast carcinoma and ER, PR, and EGFR2 status in the breast duct carcinoma variants.