3. Selective dissection of the neck with the identification of the sentinel lymph node

In the cases where more than 20% of occult metastases are expected, we decide for the selective dissection, which means the removal of the lymphatics of the regions in which the metastases are expected [8–10]. In the oral cavity cancer and the oral pharynx, this depends on the localization of the tumor. In the tumors that are close to the midline, we must make a decision about the unilateral or bilateral removal of the lymph nodes. The decision can be made easier with the use of scintigraphy which can show us where the lymph from the region of the tumor drains. We remove the region of the neck which contains the sentinel lymph and additionally two adjoining regions. If the lymph is draining to both sides of the neck, we perform a bilateral selective dissection.

It has been proven that the survival of the patients in whom the elective dissection has been done is increased compared to the patients where the dissection was only done after the appearance of the metastases [14].

The patient disfiguring after an elective selective dissection is relatively minor when performed by an experienced surgeon. However, there is always a certain esthetic deformation larger than the one where only a sentinel lymph node is removed. There is also always a risk of damaging the marginal, accessory, lingual, and hypoglossal nerves. This nerve damage is rare in a careful surgical dissection.

After the removal of the lymphatics of the determined regions, we identify and remove the sentinel lymph node from the dissected material. The node is then examined by the pathologist with the serial slices at 100–150 microns and immunohistochemical staining. The remaining lymph nodes are examined with the classical histopathological methods with one or two slices along the longitudinal axis and staining with hematoxylin and eosin.
