Aims: Gastric hyperplastic polyps (GHPs) are the most common polypoid lesion of the stomach, and their malignant potential has been demonstrated. In the present study, we evaluated the mucin phenotypes of GHPs and investigated the relationships among mucin phenotypes and clinical-pathological factors, proliferative activity and p53 expression in GHPs.
Methods: The CD10, MUC2, MUC5AC and MUC6 expression patterns of 238 GHPs were examined by immunohistochemical staining. The GHP mucin phenotypes were divided into 4 subtypes: the gastric mucin phenotype (G-type), the intestinal mucin phenotype (I-type), the mixed or gastrointestinal mucin phenotype (GI-type) and the unclassified mucin phenotype (U-type).
Results: The G and GI types were observed in 58% and 42% of the GHPs, respectively. However, no I or U type GHPs were found in the present study. The GI type was more common in lesions with dysplasia or carcinoma than in polyps without dysplasia or carcinoma (P<0.001). P53-positivity rate and high index of Ki-67 tumors were significantly more common in the GI-type than in the G-type polyps (P<0.001).
Conclusions: The mucin phenotype may serve as a useful marker for the malignant potential of GHPs, and GI-type GHPs should be considered to be a lesion with malignant potential.