ERBB2 and metastatic malignant neoplasm in the lymph nodes: Gong et al.16 found 98% and 94% concordance between HER2 status in primary versus loco-regional recurrent lesions and in primary versus distant metastatic lesions, whereas Santinelli et al. evaluated HER2 status by IHC and FISH in primary and metastatic lesions and found relatively few cases with discordant status.15 Furthermore, in one GC study, no discrepant case was found by FISH between 49 paired primary and lymph node metastasis lesions.20 We believe that these controversial results were probably due to the small number of samples examined.