Spontaneous regression of advanced-stage oropharyngeal squamous cell carcinoma.

BACKGROUND: Spontaneous regression is defined as the partial or complete disappearance of a malignant tumour proven by microscopic examination in the absence of any substantial treatment. This paper presents the case of an older woman whose advanced-stage tonsillar squamous cell carcinoma was noted to have spontaneously regressed at seven months. CASE REPORT: A 66-year-old woman presented with a 4-month history of dysphagia and odynophagia in September 2020. An exophytic tumour was seen on the right tonsil; this was diagnosed radiologically and histologically as a squamous cell carcinoma of the tonsils, with tumour-node-metastasis staging of T4aN0M0. The patient received best supportive care. Seven months later, the oropharyngeal lesion had disappeared, with no treatment. Subsequent computed tomography imaging showed radiological resolution of the previously noted right-sided oropharyngeal lesion. CONCLUSION: Several mechanisms of spontaneous regression are discussed. Further studies should review this case in conjunction with other reports of spontaneous tumour regressions, to elucidate underlying mechanisms.