The isolated symptom of unilateral tonsillar enlargement has limited value in adults with a suspected head and neck cancer pathway.

Given the uncertainty regarding the predictive value of unilateral tonsillar enlargement and/or lesion in malignancies, this study aimed to evaluate the efficacy of unilateral tonsillar enlargement and/or lesion referral criterion in the adult suspected head and neck cancer pathway. All two-week wait referrals received in 2018-2019 were reviewed. All patients referred with unilateral tonsillar enlargement and/or lesion were included and analysed for patient demographic data, presenting symptoms, initial clinic outcomes and final diagnoses. A total of 4934 urgent head and neck cancer referrals were analysed, and 1.9 per cent of these had unilateral tonsillar enlargement and/or lesion. Only 10 patients were diagnosed with tonsil cancer. All the positive tonsil cancer cases had at least one additional head and neck red flag symptom. The referral criterion for unilateral tonsillar enlargement and/or lesion may be of limited benefit in an already economically challenged National Health Service. Further multicentre studies should be undertaken to refine conclusions on the value of unilateral tonsillar enlargement and/or lesion alone as a criterion for the head and neck cancer two-week wait pathway.