Discrepancies between Pathological Examination and Imaging Analysis after Neoadjuvant Chemotherapy for a Patient with Local Advanced Breast Cancer

Abstract

CT and MRI have been used in combination with pathological examination in order to evaluate the efficacy of NAC. We present a case that showed discrepancies between the pathological findings and those of imaging analysis after NAC. We administered NAC to a patient with stage IIIB locally-advanced breast cancer. NAC showed remarkable drug efficacy. Clinical tumor response evaluated by CT and MRI showed a residual tumor. However, the pathological tumor response following NAC was grade 2b according to criteria of the Japanese Breast Cancer Society. Inaccurate determination of a residual tumor by MRI (a residual tumor diagnosed by MRI but a pathological complete response diagnosed by pathological examination) can occur occasionally.