Intravascular Metastasis in a Case of Medullary Carcinoma of the Thyroid: A Quintessential Case

Background: Medullary carcinoma of the thyroid arises from parafollicular gland cells and accounts for 3-5% of all thyroid malignancies.It rarely penetrates the internal jugular vein and can propagate antegrade or retrograde.Case description: We present a unique case of medullary carcinoma of the thyroid with internal jugular vein permeation, which was managed by total thyroidectomy with intravascular tumor clearance and meticulous vascular repair.Conclusion: Tumor clearance through the incision, tumor removal, and vascular reconstruction can effectively manage the vascular permeation of thyroid malignancy.Clinical significance: The medullary thyroid carcinoma has not yet been reported to have metastasized in the jugular vein.Hence, this case is of the utmost importance in the management protocol of medullary thyroid cancer research.