Isolated metastatic papillary thyroid carcinoma masquerading as parapharyngeal space paraganglioma

Abstract

Isolated metastatic deposits of papillary thyroid carcinoma to the parapharyngeal space are rare. Herein, we describe the case of a young woman who presented with a right-sided oropharyngeal mass that was initially diagnosed as a parapharyngeal space paraganglioma. The patient opted for conservative treatment as she was asymptomatic and wished to avoid the risk of neurovascular morbidity associated with surgery. After 20 years, the patient sought treatment again for the oropharyngeal mass, which had progressively increased in size and was causing difficulty in swallowing. Repeat imaging of the affected area revealed that the mass had increased significantly in size; it also revealed the presence of a previously absent small lesion in the right lobe of the thyroid. Excision of the parapharyngeal space tumour and near-total thyroidectomy were performed; the excised specimens showed features of the follicular variant of papillary thyroid carcinoma. As papillary thyroid carcinoma that metastasises to the parapharyngeal space can masquerade as a paraganglioma, clinicians should bear in mind that an isolated metastatic deposit in the parapharyngeal space could be the first sign of occult papillary thyroid carcinoma.