Incidence of synchronous contralateral tonsillar malignancy in a known case of unilateral tonsillar carcinoma

Objective The literature is divided with regards to contralateral tonsillectomy in a known/suspected case of ipsilateral tonsillar malignancy. In this study, we evaluate the incidence of indolent synchronous contralateral tonsillar malignancy (SCTC) in patients with known ipsilateral tonsillar malignancy. Methods All patients diagnosed with ipsilateral tonsillar carcinoma (TC) at a tertiary teaching center between January 2016 and December 2019 were screened. None of the patients were suspected to have bilateral TC. All patients underwent appropriate imaging in the form of Magnetic resonance imaging and computed tomography of head and neck region and then underwent bilateral tonsillectomy. The prevalence of bilateral tonsillar malignancy and the factors predicting them were analyzed. Results In all 59 patients were included in the study. The mean and median age of the patient population was 60.8 and 59 years, respectively, with a male to female ratio of 3.2:1. The incidence of bilateral tonsillar malignancy in carcinoma of unknown primary (CUP) was 3/10 (33.3%). Among the remaining 49 patients, incidence of synchronous contralateral tonsillar carcinoma (SCTC) was 2/49 (4.08%). Overall, 5/59 (8.5%) patients had synchronous bilateral tonsillar malignancy. Furthermore, dysplasia was found in the contralateral tonsil in 4/10 (40%) CUP patients. Among the remaining 49 patients, dysplasia was seen in the contralateral tonsil in 20/49 (40.8%) patients. The absence of p16 expression predicted higher probability of SCTC. Factors like gender, T stage, nodal status or smoking did not predict SCTC. Conclusion We recommend bilateral tonsillectomy in all patients with suspected or proven TC (unilateral or bilateral) and CUP as it helps identify indolent SCTC and it does not add any significant morbidity to the patients. Level of evidence : III.