<prompt> In radical neck dissection, which structure is not removed: March 2005, Marclz 2013 a, eCervical group of lymph nodesSternocleidomastoid muscleInternal jugular veinNone of the above  <response>: Ans. D: None of the above The radical neck dissection RND is defined as removing all of the lymphatic tissue in regions I-V including removal of the spinal accessory nerve, SAN, sternocleidomastoid muscle SCM, and internal jugular vein IJV. It does not include removal of the suboccipital nodes, periparotid nodes except for infraparotid nodes located in the posterior aspect of the submandibular triangle, buccal nodes, retropharyngeal nodes, or paratracheal nodes. Modified Radical Neck Dissection MRND - removal of all lymph node groups routinely removed in a RND, but with preservation of one or more nonlymphatic structures SAN, SCM and IJV. Selective Neck Dissection SND together with the use of parentheses to denote the levels or sublevels removed - cervical lymphadenectomy with preservation of one or more lymph node groups that are routinely removed in a RND. Thus for oral cavity cancers, SND I-III is commonly performed. For oropharyngeal, hypopharyngeal and laryngeal cancers, SND II-IV is the procedure of choice. Extended Neck Dissection - This refers to removal of one or more additional lymph node groups or nonlymphatic structures, or both, not encompassed by the RND 