Neck management in medullary thyroid carcinoma

The aims of this study were to retrospectively evaluate incidence and patterns of lymph node metastases, surgical treatment and prognostic factors of medullary thyroid carcinoma.

Out of a group of 70 MTC patients data of 67 patients were collected. Sixty-two of these patients underwent surgery. Apart from thyroidectomy, 16 patients underwent a bilateral neck dissection, 21 a unilateral neck dissection and 29 a paratracheal dissection or node-picking operation. Thirty-six patients were irradiated, of which 31 postoperatively and five with palliative intent.

Lymph node metastases were found in 91% of the ipsilateral neck dissection specimens, 91% of the paratracheal dissections and 63% of the contralateral dissections. Of the 12 elective neck dissections, 5 were tumor positive. Level VI was positive in 91% of the cases where a dissection was done, whereas preoperatively only 16% were scored tumor positive. During follow-up 22 of the 67 patients developed one or more locoregional recurrences (in total 28 recurrences). The most important factors that were correlated with a worse prognosis of survival were late stage of disease (stage III and IV) (p=0.0014), high number of positive lymph nodes (p=0.0023) and incomplete surgical resection (p=0.0002).

The high rate of locoregional recurrences in this study are a strong argument for a more aggressive approach to the primary and neck. A routine central and ipsilateral selective neck dissection of levels II-V should be considered in all MTC patients based on the high incidence of metastases and the relative low morbidity of a unilateral neck dissection. Patients referred after thyroidectomy alone with elevated (stimulated) calcitonin levels should be re-operated, performing an elective or therapeutic central and unilateral neck dissection.