What are the different types of neck dissection?

Classification of Neck Dissection Types

Modern neck dissections are classified into two main categories: comprehensive and selective neck dissections, with the choice determined by nodal stage and primary tumor location. 1, 2

Primary Classification System

Comprehensive Neck Dissection

• Removes all lymph node groups (levels I-V) that would be included in a classic radical neck dissection 1
• The classification as "comprehensive" is independent of whether the sternocleidomastoid muscle, internal jugular vein, or spinal accessory nerve is preserved 1
• Recommended for N3 disease 1, 2, 3
• Generally preferred for N1-N2 disease when therapeutic intent is needed, as disease often extends beyond selective dissection bounds 1, 3

Selective Neck Dissection

• Encompasses three or fewer nodal levels based on predictable patterns of lymphatic spread from the primary tumor 2, 3
• Recommended for N0 disease 1, 2, 3
• May be appropriate for selected N1-N2 patients with low tumor burden 3
• Typically includes 6 or more lymph nodes on histologic examination 2

Site-Specific Selective Dissection Patterns

Oral Cavity Tumors (N0)

• Selective neck dissection typically includes levels I-III (supraomohyoid dissection) 2, 4

Oropharynx Tumors (N0)

• Selective neck dissection typically includes levels II-IV 2, 3

Laryngeal and Hypopharyngeal Primaries (N0)

• Selective neck dissection includes levels II-IV, with level VI added for infraglottic laryngeal cancers 3
• Level I is rarely at risk from these primary sites 2
• A dissection of levels II-VI should be described as an "extended selective neck dissection" 2

Parotid Malignancies

• Ipsilateral selective neck dissection of levels II-IV is recommended for T3-T4 tumors and high-grade malignancies 3

Laterality Considerations

Bilateral neck dissection is indicated for:

• Tumors at or near the midline 1, 3
• Tumor sites with bilateral drainage (base of tongue, palate, supraglottic larynx, deep space pre-epiglottic involvement) 3
• Midline posterior scalp tumors 5

Extended Neck Dissection

This category applies when standard structures plus additional nonlymphatic structures must be removed 6:

• Skin, digastric muscle, hypoglossal nerve, vagus nerve, sympathetic chain, ramus mandibularis, carotid artery, or tracheo-esophageal nodes 6
• Typically necessary for N2 and N3 disease with extensive involvement 6
• Local control achieved in approximately 70% of cases 6

Critical Pitfalls to Avoid

• Do not perform selective neck dissection for clinically evident nodal disease beyond N1-N2a; these patients require comprehensive dissection 3
• Do not omit level VI dissection for infraglottic laryngeal cancers, as this level is frequently involved 3
• Do not perform unilateral dissection for midline tumors, as bilateral drainage mandates bilateral treatment 3
• The most difficult region for local control is disease behind the mastoid process and involvement of subdermal lymphatics 6

Specimen Handling

• The neck dissection specimen should be oriented or sectioned to identify lymph node levels for accurate pathologic staging 3, 5
• Comprehensive neck dissection specimens usually include 10 or more lymph nodes 2