Contemporary management of tonsillar schwannoma: a systematic review

Background: Tonsillar schwannoma is a rare neoplastic disease representing one percent of all head and neck schwannomas. Current literature on tonsillar schwannoma consists mainly of case reports, with no clear guidelines for clinical workup and management. This systematic review summarises the clinical features, diagnostic workup and management of tonsillar schwannoma with the aim of providing guidance for the treatment of this rare disease. Methods: A systematic review was conducted of all patients with palatine tonsil schwannoma in the available literature. A search of PubMed, Medline and Embase databases was conducted on 5^th May 2023 to identify all published cases. Articles in a non-English language were excluded from the study. The final list of studies included were reviewed by both authors and assessed for bias using the Joanna Briggs Institute (JBI) checklist standardised tool for case reports. Data was reviewed and extracted from cases with a final diagnosis of palatine tonsil schwannoma in both adult and paediatric populations. Data was electronically collated and descriptive statistical analysis and qualitative review of the data was conducted using Microsoft Excel. Results: A total of thirteen patients from thirteen cases studies were included in this systematic review. We found that this condition was present within a broad age range (eight to seventy-four years of age) and affected females (nine cases) more than males (four cases). There were two main reasons patients presented for review—progressive dysphagia and noticing a mass on intra-oral self-examination. Clinical examination findings were consistent among the case reports, with no evidence to suggest a malignant lesion. In all cases, patients underwent at least one form of imaging, which showed the lesion had features consistent with a schwannoma. Only three patients underwent a fine needle aspiration of the lesion, which produced a non-diagnostic result. Definitive management was unilateral tonsillectomy or tonsillotomy and there was no documented recurrence, although the follow-up period was highly variable. Conclusions: In clinical practice, unilateral palatine tonsillar masses are treated as malignancy until proven otherwise, and thorough history and examination will determine the level of clinical suspicion. In all cases surgical excision was the definitive management for this condition, but there was high variability in investigations and follow-up among the reported cases. Our management algorithm proposes one form of imaging is sufficient and pre-operatively biopsy is not required. We also aim to standardise follow-up at six to eight weeks post procedure and then again in six to twelve months to rule out recurrence.