Invasive Breast Carcinoma Tumor Size on Core Needle Biopsy: Analysis of Practice Patterns and Effect on Final Pathologic Tumor Stage

Our study revealed that in most cases, the largest tumor size is found in the excision/mastectomy specimen. However, in 9.4% (82 of 870), the CNB contains the most accurate tumor size for pT staging. On the basis of our results, including the largest linear tumor extent on the CNB report is recommended.