Clinicopathological and molecular analyses of hyperplastic lesions including microvesicular variant and goblet cell rich variant hyperplastic polyps and hyperplastic nodules—Hyperplastic nodule is an independent histological entity

• Published in: Pathology international Vol. 72; no. 2; pp. 128 - 137
• Main Authors: Uesugi, Noriyuki, Ajioka, Yoichi, Arai, Tomio, Tanaka, Yoshihito, Sugai, Tamotsu
• Format: Journal Article
• Language: English
• Published: Australia Wiley Subscription Services, Inc 01.02.2022; John Wiley and Sons Inc
• Subjects: Adult; Aged; Aged, 80 and over; Cluster analysis; DNA Methylation; Female; Goblet Cells - pathology; goblet cell‐rich variant; Humans; Hyperplasia - genetics; Hyperplasia - pathology; hyperplastic nodule; hyperplastic polyp; Immunohistochemistry; KRAS mutation; Lesions; Male; Middle Aged; Mucin; Mutation; Nodules; Original; p53 Protein; Phenotypes; Polyps; Proto-Oncogene Proteins B-raf - genetics; Proto-Oncogene Proteins B-raf - metabolism; Proto-Oncogene Proteins p21(ras) - genetics; Proto-Oncogene Proteins p21(ras) - metabolism; Subgroups; KRAS mutation; hyperplastic nodule; hyperplastic polyp; goblet cell-rich variant
• DOI: 10.1111/pin.13187
• ISSN: 1320-5463

Hyperplastic nodules (HNs) have been considered to be hyperplastic lesions among Japanese pathologists, although they have not been recognized worldwide. Here, we examined clinicopathological and molecular differences between goblet cell‐rich variant hyperplastic polyp (GCHPs), microvesicular variant HPs (MVHPs), and HNs. Patients with hyperplastic lesions including 61 GCHPs, 62 MVHPs, and 19 HNs were enrolled in the present study. The clinicopathological and molecular features examined included the mucin phenotype expression, p53 overexpression, annexin A10, genetic mutations (BRAF and KRAS), and DNA methylation status (low, intermediate, and high methylation epigenotype). In addition, hierarchical cluster analysis was also performed to identify patterns among the histological features. The lesions were stratified into three subgroups and each lesion was assigned into a subgroup. While GCHP was associated with KRAS mutation, MVHP was closely associated with BRAF mutation; no mutation was found in HN. We list specific histological findings that corresponded to each lesion. Finally, there were no significant differences in the methylation status among lesions. The current result shows that both MVHPs and GCHPs have a neoplastic nature whereas HN is non‐neoplastic. We suggest that HNs should be distinguished from HPs, in particular GCHPs, in terms of pathological and genetic features.