Should the Contralateral Tonsil Be Removed in Cases of <scp>HPV</scp>‐Positive Squamous Cell Carcinoma of the Tonsil?

Abstract

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.1 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.2 Furthermore, synchronous tumors are defined as those that occur simultaneously with the index cancer; these tumors are present in approximately 4% of cases.2 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.3 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.4 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)? Several case reports have described cases of SBTC. Roeser et al.5 presented a 51-year-old male with a left cystic neck mass consistent with SCC by fine needle aspiration. A positron emission tomography-computed tomography (PET-CT), however, demonstrated asymmetric fluorodeoxyglucose (FDG) activity in the contralateral palatine tonsil and neck. This patient ultimately underwent bilateral transoral robotic surgery (TORS) oropharyngectomy, which confirmed a diagnosis of SBTC. Similarly, Theodoraki et al.4 presented the case of SBTC in a 52-year-old male with a preoperative diagnosis of cancer of unknown primary (CUP). Although both tonsillar sites appeared unsuspicious clinically, a PET-CT revealed ipsilateral enhancement of the tonsil area. The final pathology revealed SBTC. In both cases, although the clinical exam appeared benign, PET-CT findings guided surgical management by demonstrating suspicious activity in the tonsil. Dziegielewski et al.2 performed a retrospective review specifically in patients who underwent TORS for known tonsillar cancer. Of the 79 consecutive patients with HPV+ TSCC who underwent primary TORS radical tonsillectomy, 30 patients also underwent contralateral tonsillectomy. They found that three patients (10%) had SBTC on final pathology. None of these three patients had a SBTC identified on preoperative PET-CT or clinical examination. Furthermore, they found no differences in complications, gastrostomy tube rates, or length of stay (P > 0.05) between patients who underwent unilateral versus bilateral tonsillectomy. The only statistically significant difference was an increased operative blood loss of 11.5 cc more in the patients who underwent bilateral surgery (P = .001). Of note, contrary to the findings from Roeser et al.5 and Theodoraki et al.,4 Dziegielewski et al.2 found that the contralateral tonsil exhibited metabolic activity at physiological levels on PET-CT in their three patients. These authors caution that contralateral TSCC may be more indolent and easily missed on imaging and thus recommend that all patients who are undergoing primary TORS for TSCC also undergo contralateral tonsillectomy to obtain definitive tissue diagnosis. To determine the prevalence of SBTC, Rokkjaer et al.1 performed a retrospective review of all patients diagnosed with TSCC between 2000 and