Objective Patients with coronavirus disease vaccine associated lymphadenopathy are increasingly being referred to healthcare services. This work is the first to report on the incidence, clinical course and imaging features of coronavirus disease vaccine associated cervical lymphadenopathy, with special emphasis on the implications for head and neck cancer services. Methods This was a retrospective cohort study of all patients referred to our head and neck cancer clinics between 16 December 2020 and 12 March 2021. The main outcomes measured were the proportion of patients with vaccine-associated cervical lymphadenopathy, and the clinical and imaging characteristics. Results The incidence of vaccine-associated cervical lymphadenopathy referrals was 14.8 per cent (n = 13). Five patients (38.5 per cent) had abnormal-looking enlarged and rounded nodes with increased vascularity. Only seven patients (53.9 per cent) reported full resolution within an average of 3.1 ± 2.3 weeks. Conclusion Coronavirus disease vaccine associated cervical lymphadenopathy can mimic malignant lymphadenopathy and therefore might prove challenging to diagnose and manage correctly. Healthcare services may encounter a significant increase in referrals.

Objectives: Lower neck lymphadenopathy usually harbour malignancy in around 75% of cases, and should warrant an urgent referral to the head and neck (H&N) cancer services. The presented work is the first study to report on the incidence, clinical course, and imaging features of cervical CVAL (cCVAL), with special emphasis on the implications for the H&N cancer services.Design: Retrospective cohort study.Setting: Leading UK NHS trust providing tertiary H&N cancer services.Participants: Patients referred to our H&N cancer clinics with cCVAL between 16 December 2020 and 12 March 2021 (12 weeks). We defined cCVAL as any unilateral and lower cervical lymphadenopathy, noticed within two weeks of COVID-19 vaccination in the ipsilateral deltoid muscle. Main outcome measures:The proportion of patients referred with cCVAL. Secondary outcomes included the clinical and imaging characteristics and follow-up measures.Results: From 88 patients referred with cervical lymphadenopathy, 13 patients (14.8%) had cCVAL. Pain was only reported in six patients (46.2%), but swelling was noticed by all patients within a median of four days. The average diameter of CVALs on ultrasound scans was 5.5 ± 1.4 mm, and five patients (38.5%) had abnormally looking rounded node or increased vascularity on colour doppler. Seven patients (53.9%) reported full resolution of their lymphadenopathy within an average of 3.1 ± 2.3 weeks. Conclusion:Reactive cervical CVAL can mimic malignant lymphadenopathy, and therefore might prove challenging to correctly diagnose and manage. Over the next few months, primary care and H&N cancer services should be prepared for a potentially significant increase in referrals.