MUC1 and metastatic malignant neoplasm in the lymph nodes: Certain studies have claimed that regular HE staining supplemented with immunohistochemistry [IHC; cytokeratin (CK) or epithelial membrane antigen (EMA)] may increase the detection rate of lymph node metastasis of GCA (6–8) by providing more accurate pathological information so as to guide treatment and prognosis prediction (9).