Molecular profiling of appendiceal serrated lesions, polyps and mucinous neoplasms: a single-centre experience

Giada Munari, Gianluca Businello, Paola Mattiolo, Gianmaria Pennelli, Marta Sbaraglia, Chiara Borga, Salvatore Pucciarelli, Gaya Spolverato, Claudia Mescoli, Francesca Galuppini, Antonio Sommariva, Elena Bellan, Sara Lonardi, Fotios Loupakis, Claudio Luchini, Angelo Paolo Dei Tos, Matteo Fassan

Research output: Contribution to journalArticlepeer-review


Purpose: Non-neuroendocrine neoplasms of the appendix are a phenotypically heterogeneous group of lesions; a comprehensive molecular characterization of these tumors is still lacking. Methods: A total of 52 samples taken from 49 patients was evaluated: 18 sessile serrated lesions (SSL; 3 with dysplasia), 2 high-grade tubular adenomas, 1 tubulo-villous adenoma,1 hyperplastic polyp, 18 low-grade appendiceal mucinous neoplasms (LAMN), 3 high-grade appendiceal mucinous neoplasms (HAMN) and 9 mucinous adenocarcinomas. Hotspot mutational profiling of the RNF43, SMAD4, KRAS, NRAS, BRAF and PIK3CA genes was performed. Expression of p53, MLH1, PMS2, MSH2, and MSH6 was evaluated by immunohistochemistry. Results: KRAS was the most frequently mutated gene (53.9% of cases), followed by RNF43 (15.4%), and BRAF (13.5%). In particular: KRAS was mutated in 44.4% of adenocarcinomas, 66.7% of HAMNs, 61.1% of LAMNs, 53.3% of SSL without dysplasia and in 66.7% of SSL with dysplasia; RNF43 was mutated in 33.3% of adenocarcinomas, 66.7% of HAMNs, 11.1% of LAMNs and in 6.7% of SSL without dysplasia; BRAF was mutated in 11.1% of adenocarcinomas, 26.7% of SSL without dysplasia and in 5.6% of LAMNs. Only a case of high-grade tubular adenoma showed mismatch repair deficiency, while immunohistochemical expression of p53 was altered in 21.1% of cases. Conclusions: The histological phenotypic similarities between appendicular mucinous lesions and serrated colon lesions do not reflect a similar genetic landscape. Mismatch repair deficiency is a rare event during appendiceal mucinous carcinogenesis.

Original languageEnglish
Pages (from-to)1897-1904
Number of pages8
JournalJournal of Cancer Research and Clinical Oncology
Issue number7
Publication statusPublished - Jul 2021


  • Appendiceal neoplasms
  • Biomarkers
  • Molecular pathology
  • Pseudomyxoma peritonei
  • Serrated lesions

ASJC Scopus subject areas

  • Oncology
  • Cancer Research


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