RESUMO
AIMS: The prognosis for well-differentiated thyroid carcinomas is favourable after treatment, but the rate of recurrence is around 20%. Cervical ultrasonography, radio-iodine scans, and monitoring of serum thyroglobulin (Tg) levels allow these recurrences to be diagnosed. The management of patients with isolated elevated Tg levels is controversial in the presence of negative radio-iodine scans. METHODS: The records of 57 patients diagnosed with recurrence of well-differentiated thyroid cancer were reviewed. Serum Tg was not evaluated in 31 of these patients (group 1) and measured in the other 26 cases (group 2). RESULTS: Forty-three recurrence sites were found; four deposits in the thyroid bed and 39 cervical metastatic nodes, with an average of five nodes per patient. The radio-iodine scan was accurate in detecting 10/24 of cases, radiology in 9/17, and elevated Tg levels in 20/25. Thirteen patients with recurrences diagnosed on the basis of Tg levels had negative radio-iodine scans. After surgery, Tg levels were normal in 10 patients from group 1 and 16 patients from group 2 (p=0.0078). CONCLUSIONS: Elevated Tg levels are indicative of disease progression or recurrence in patients who have previously been operated on for well-differentiated thyroid cancer. Even when the radiological study or radio-iodine scan is normal, surgical re-exploration of the neck, with total thyroidectomy and lymphadenectomy, is advisable.