Fig. 4From: The clinicopathological and immunohistochemical features of breast carcinomas with signet-ring-cell differentiationHistochemical staining findings (magnification×400). A,B Acidic mucus was stained with AB (pH 2.5) and turned blue. C,D Nutral mucus was stained with PAS, and turned red. E,F Mixed type mucus was purplish red after staining with AB (pH 2.5)-PASBack to article page