Review of Distribution of Nodal Disease in Differentiated Thyroid Cancers in an Oncosurgical Center in Sri Lanka

There are not many publications on the prognostic implications of nodal disease in patients with papillary thyroid cancers (PTC). This study explored the distribution of nodes with respect to the levels, optimal management of the neck for patients with PTC, and its survival advantages.

Followup of 79 patients with thyroid cancer (59 with PTC) at the National Cancer Institute, Maharagama, Sri Lanka, was analyzed.

The most common histologic type of all thyroid cancers presenting to the Institute was differentiated PTC which affected 59 patients (74.7%). Of them, 29 (50.0%) had positive lymph node metastases in the neck these nodes were found on clinical examination and confirmed by ultrasound in all. Therfore necessitating a comprehensive neck dissection. Among the patients with nodal disease, 5 had nodes in Level 1 at the time of presentation. All patients in this group had multiple levels of positive nodes. Metachronous nodal disease was found in 9 (31.4%) patients, with a disease-free period ranging from 2 months to 37 years. Among the patients with nodal disease, 13 had a single nodal group involvement and the majority of these were Level 4 nodes (46.2%). Central node (Level 6) involvement was found in nine (15.3%) patients. Multiple nodal group involvement indicating multifocal disease was present in 16 (27.6%) patients. Extracapsular nodal spread at presentation and extracapsular thyroid disease at presentation was 10 (16.9%) and 17 (28.8%), respectively. Nodal neck recurrences during followup were present in 2 patients.

Level 1 nodal metastases was present if 5 (8.5%) patients in our group. It is recommended that Level 1 nodes be explored during neck resection for PTC. Because 27.6% of the patients had multifocal disease, it may be important to recommend inclusion of a Level 1 clearance in the presence of multiple nodal involvement. There is a subgroup of patients who had highly aggressive nodes, indicated by extracapsular penetration, which even after radical clearance and external beam radiotherapy have a tendency to recur locally. This indicates an important prognostic feature of the nodal disease in PTC. Because 27.6% of the patients studies had multifocal nodal disease, we consider a comprehensive nodal clearance is necessary for patients with clinically positive nodes.