Introduction <p>Medullary thyroid carcinoma is a neuroendocrine tumor derived from the parafollicular C cells of the thyroid gland. Progressive or atypical cervical symptoms after prior spine surgery may have vertebrogenic or nonvertebrogenic causes and warrant careful evaluation.</p> Case presentation <p>A 57-year-old non-Hispanic White female with a history of anterior cervical discectomy presented with progressive right-sided neck swelling, throat tightness, dysphagia, and hoarseness. She first noticed a small lump on the right side of her neck approximately one year after her cervical procedure, with gradual enlargement over the following decade and more rapid progression later. Fine-needle aspiration and soft-tissue computed tomography of the neck showed findings concerning for malignancy. She subsequently underwent total thyroidectomy with cervical lymph node dissection, and histopathologic analysis confirmed medullary thyroid carcinoma with metastatic involvement of right cervical lymph nodes.</p> Conclusion <p>This case highlights the importance of maintaining a broad differential diagnosis in patients with progressive cervical symptoms or neck masses after prior cervical spine surgery. Although no causal relationship can be established between anterior cervical discectomy and medullary thyroid carcinoma, clinicians should remain alert to nonvertebrogenic and potentially malignant causes when the clinical course is atypical or progressive.</p>