Thyroid carcinoma discovered incidentally during surgical resection of head and neck squamous cell carcinoma: A case series

The occurrence of 2 synchronous primary cancers of different origin in the head and neck region is rare. The incidence of thyroid carcinoma found during surgical resection of primary oral squamous cell carcinoma (SCCa) is about 0.3% to 1.9% of patients. Because of the rarity of cases, there is no consensus on management. To clarify significance and management of such lesions, we report 13 cases in which incidental thyroid carcinoma was discovered during surgical resection for primary oral SCCa. A total of 1295 cases of head and neck SCCa from a 4-year period were reviewed, of which we found 13 cases of concurrent thyroid malignancy, providing an incidence rate of approximately 1%. Of these patients, 61.5% received a total or hemithyroidectomy and, of those, 62.5% received radioactive iodine for their thyroid carcinoma; 38.4% did not receive treatment for their thyroid malignancy. The mortality rate for this case series was 23%, of which all deaths were attributed to complications from SCCa. There were no cases where mortality was related to the thyroid carcinoma. Overall, this is consistent with the consensus that incidental thyroid carcinoma found during oral SCCa resection is insignificant compared with the aggressiveness of the primary malignancy. (Oral Surg Oral Med Oral Pathol Oral Radiol 2021;132:e190-e197)