A rare incidence of mandibular metastasis of papillary thyroid carcinoma: A case report and review of literature.

Papillary Thyroid Carcinoma (PTC) primarily metastasizes via regional lymphatics making its spread to the oral cavity exceedingly rare. Although this disease remains the most common endocrine malignancy, comprising roughly 85%-90% of all thyroid cancers, its occurrence within the oral cavity happens in less than 1% of oral malignancies. This study identifies a case involving a 77-year-old male with a history of well-differentiated PTC that was initially treated with a total thyroidectomy and adjuvant radioactive iodine. Five years after his initial treatment, surveillance imaging demonstrated a 3 cm expansile mass of the left mandible. An incisional biopsy then confirmed the diagnosis of metastatic PTC. A segmental resection of his mandible was completed with final reconstruction utilizing a fibula free flap. Given the limited number of cases involving metastatic spread of PTC to the oral cavity, a standardized treatment algorithm does not exist. Thus, this case serves to provide a documented report of this rare occurrence and to review literature that may help other clinicians treat patients with this malignancy type. There remains a need for future studies to create risk stratification models for patients with metastatic PTC that consider margin analysis, genetic characteristics, and risk factors to tailor individual treatment plans.