Discordance in routine second opinion pathology review of head and neck oncology specimens: A single-center five year retrospective review

•Mandatory second opinion pathology slide review for new referrals is a common practice.•We conducted a retrospective cohort study to investigate the discordance rate.•Of 667 new head and neck cancer referrals cases over 5 years, 22% were discordant.•Histology but not biopsy site were associated with discordance on multivariate models.•Routine slide review may reveal information that alters the treatment course.