Should the Contralateral Tonsil Be Removed in Cases of HPV-Positive Squamous Cell Carcinoma of the Tonsil?

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Background

Human papillomavirus-positive (HPV+) head and neck squamous cell carcinomas (SCC) are increasing in incidence worldwide. The palatine tonsils are the most commonly involved anatomical subsite, followed by the base of tongue and then the soft palate. Secondary primary malignancy (SPM) is a well-established phenomenon among patients with head and neck SCC and can present in up to 36% of patients within 20 years of their original diagnosis. Furthermore, synchronous tumors are defined as those that occur simultaneously with the index cancer; these tumors are present in approximately 4% of cases.

SPM is thought to arise secondary to field cancerization, a biological process by which prolonged exposure to carcinogens leads to independent malignant transformation at multiple sites. The prevalence of synchronous bilateral HPV+ SCC of the tonsil (SBTC) is largely unknown, and there is much controversy regarding routinely removing the contralateral tonsil. Fear of increased pain, bleeding, circumferential scarring, and functional impairment have all been cited as reasons to avoid contralateral tonsillectomy in these scenarios. Proponents of contralateral tonsillectomy, however, raise concerns over the potentially fatal consequences of missing occult contralateral disease. Another advantage is the resulting symmetric appearance of the palatal arches, which allows for improved oncologic surveillance and easier detection of tumor recurrence.

Given the important prognostic and therapeutic implications of identifying a SBTC, should the contralateral tonsil routinely be removed in cases of HPV+ squamous cell carcinoma of the tonsil (TSCC)?

Best Practice

The contralateral tonsil should routinely be removed in cases of suspected or known unilateral HPV+ TSCC. Furthermore, preoperative clinical exam findings and imaging studies including PET-CT should not be used to exclude the possibility of SBTC. Although there are reports of significant complications resulting from bilateral radical surgery, performing a routine contralateral tonsillectomy does not appear to increase rates of morbidity or complications, and the resulting symmetric palatal arch could potentially improve oncologic surveillance and detection of recurrence.

Furthermore, identifying a contralateral TSCC can dramatically alter treatment and prognosis. The patient may need further surgery and/or radiation therapy to the contralateral oropharynx and neck, which otherwise would not be indicated in unilateral disease. Although the true incidence of SBTC remains unknown, the oncologic outcome of missing the second primary and delaying treatment can be devastating and even fatal. Future prospective studies should be performed to identify any clinical disparities or differences in tumor characteristics that could improve preoperative identification of SBTC patients (Laryngoscope. 2019;129:1257–1258).

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