Occurrence of thyroid carcinoma after radiotherapy to the head and neck region

History and clinical findings: A 73-year-old woman was hospitalised because of increasing dyspnoea and hoarseness after a bout of acute tracheobronchitis. She had been receiving levothyroxine for a growing grade III nodular goitre. At the ages of 26 and 29 she had been treated for cervical lymph node tuberculosis with local excision and percutaneous radiotherapy of 8 Gy each time. On examination she was found to have a bulging neck profile and a hard, practically immobile node in the left lobe of the thyroid. Investigations: Laboratory tests showed a euthyroid metabolic state, while ultrasound demonstrated a mass, 40 mm in diameter, scintigraphically a cold nodule. A fine-needle biopsy was cytologically highly suspicious of neoplasm. Treatment and course: Surgical exploration of the neck and mediastinum revealed an insular follicular carcinoma (10 cm in diameter), involving the right recurrent laryngeal nerve and surrounding the brachiocephalic trunk. The latter had to be removed and a Gore-Tex graft was interposed. Postoperative radiotherapy was given (150 mCurie I-131). Conclusion: An enlarging nodular goitre, occurring after a latent period of years following radiotherapy to the neck region for benign and (or) malignant disease, especially when it had been administered in childhood or young adulthood, should raise the suspicion of a radiogenic thyroid carcinoma. Definitive diagnosis by fine-needle biopsy is essential.