Definition of Dissection, neck
Dissection, neck: Surgery in which the neck is opened -- to "dissect" means to "cut apart" -- in order to identify, examine, and sometimes remove structures such as lymph nodes or other tissue for diagnosis or treatment.
A radical neck dissection involves removal of a tumor from the neck with an additional margin of apparently normal tissue of at least 2 cm, as well as removal of the lymph nodes from the neck.