How is grading of breast carcinoma?

➢ All types of invasive breast carcinoma are assigned a grade from 1 (low-grade) to 3 (high-grade) based on : 1. nuclear pleomorphism, 2. tubule formation, 3. Proliferation. ➢ Low-grade nuclei are similar in appearance to the nuclei of normal cells. ➢ High-grade nuclei are enlarged and have irregular nuclear contours resulting from abnormal DNA content and structure ➢ Most low-grade carcinomas form well-defined tubules and may be difficult to distinguish from benign lesions, whereas highgrade carcinomas lose this capacity and invade as solid sheets or single cells. ➢ Proliferation is evaluated by counting mitotic figures. ➢ The majority of HER2-positive and triple-negative carcinomas are highly proliferative ➢ whereas ER-positive cancers show a wide range of proliferation