Neck dissection for surgical treatment of lymphnode metastasis in papillary thyroid carcinoma.

In papillary thyroid carcinoma lymphnode metastases at presentation do not seem to adversely affect survival, but do increase the risk of loco-regional tumor recurrence. The value of systematic versus selective lymphadenectomy is far less standardized, whereas the role of postoperative radioiodine in preventing either nodal recurrence or cancer death remains controversial. Clinical data of 36 N+ patients with papillary thyroid carcinoma who had undergone from 1990 to 1996 ipsilateral or bilateral neck dissection were retrospectively reviewed, to analyse the value of systematic lymphadenectomy. In our series of 50 extensive lymph node dissections (levels 2-6), the number of metastases in each specimen (mean value: 5) and the incidence of multiple level metastases (36%) were high. In 37.5% of the metastases at level 6 and in 11.1% at level 4, coexisting nodal involvement at level 2 was observed, without metastasization at intermediate levels. Multiple levels metastases and skip metastases were present in at least one third of the patients and could be excised only performing a complete dissection of the levels 2-6. Extra-capsular spread was found in 56% of the specimens. In 64.3% of these cases a functional neck dissection was performed. A modified radical or radical neck dissection was carried out in the other 35.7% of the cases. These patients received modified radical neck dissection (functional dissection with sacrifice of internal jugular vein) in 60% of the cases and radical neck dissection in the other 40%. In papillary thyroid carcinoma extensive lymphnode dissection at presentation has been stated to offer no advantage versus selective lymphadenectomy, causing increased morbidity. However, experienced surgeons report a low incidence (less than 5%) of accessory spinal nerve and cervical plexus permanent sequelae after functional neck dissection. In our opinion, patients with cervical lymph node metastases require a complete loco-regional neck dissection. Systematic lymphadenectomy, performed by lateral neck plus upper anterior mediastinal dissection, can yield a high disease-free survival. Moreover, this can limit the overall radio-iodine therapeutic dose and the risk of de-differentiation of recurrent tumor to the anaplastic type in patients with a long-term and near normal life-span.