Papillary thyroid carcinoma incidentally identified in a neck dissection specimen for tongue squamous cell carcinoma: A case report and literature review

Lymph node metastasis of thyroid carcinoma identified within neck dissection specimens for oral cancer is exceedingly rare, and no standardized approach currently exists for its management, including the investigation of a primary lesion. We report a case in which papillary thyroid carcinoma (PTC) was incidentally detected in a neck dissection specimen obtained during surgery for tongue cancer, ultimately leading to the identification of the primary lesion. The patient underwent subtotal glossectomy, bilateral neck dissection, and anterolateral thigh flap reconstruction for squamous cell carcinoma of the tongue (cT3N0M0). A minute proliferative focus of PTC was identified in a right level III cervical lymph node. Imaging of the thyroid gland revealed no lesions suggestive of a primary tumor. However, right hemithyroidectomy for further evaluation revealed a microscopic intrathyroidal focus of PTC, measuring less than 1 mm. Given the anatomical overlap in lymphatic drainage between the oral cavity and thyroid gland, clinicians should be aware of the potential for incidental thyroid pathology during head and neck oncologic procedures. We present this case alongside a comprehensive literature review focusing on the current understanding and management strategies for incidentally detected thyroid carcinoma within neck dissection specimens obtained during surgery for oral cancer.