Which lymph nodes are involved in scalp lesions?

Lymph Node Drainage Patterns for Scalp Lesions

Scalp lesions most commonly drain to the occipital, posterior auricular, and level II cervical lymph nodes, with specific drainage patterns determined by the anatomical location of the lesion on the scalp.

Primary Drainage Patterns by Scalp Region

• Posterior Scalp: Primarily drains to the occipital lymph nodes 1, 2, 3
• Temporal Region: Drains to level II cervical lymph nodes and parotid lymph nodes 3
• Parietal Region: Has distinct drainage patterns and is associated with poorer prognosis compared to other scalp regions 4
• Frontal Scalp: Drains to level II cervical lymph nodes and parotid lymph nodes 3

Common Lymph Node Basins for Scalp Lesions

• Level II Cervical Lymph Nodes: Most common location for sentinel lymph nodes (SLNs) from scalp lesions, involved in approximately 48% of cases 2
• Occipital Lymph Nodes: Critical drainage site for posterior scalp lesions 3
• Posterior Auricular Lymph Nodes: Important drainage site, particularly for lesions in the temporal and posterior regions 2
• Parotid Lymph Nodes: Common drainage site for anterior and lateral scalp lesions 3
• External Jugular Lymph Nodes: Present in over 15% of all head and neck cutaneous malignancy cases 1

Clinical Significance

• Scalp sentinel lymph nodes (classified as posterior auricular or occipital) are identified in 26% of patients with scalp melanoma 2
• When scalp SLNs are identified, approximately 30% harbor metastatic disease, highlighting their clinical importance 2
• Level IIB lymph nodes are involved in 15.9% of all head and neck cutaneous malignancy cases 1

Important Considerations

• Hair-bearing scalp lesions have significantly worse prognosis than non-hair-bearing areas (5-year survival 47% vs. 86%) 4
• Lesions posterior to the mid-tragal line have different drainage patterns and prognosis compared to anterior lesions 4
• Nontraditional lymph node locations (external jugular, perifacial, suboccipital, postauricular, and parotid) are important sites of drainage that should not be overlooked 1

Clinical Implications

• Understanding these drainage patterns is essential for:

  • Accurate sentinel lymph node biopsy planning 1, 2
  • Guiding elective and completion neck lymphadenectomy 1
  • Planning radiation fields when indicated 1
  • Directing long-term surveillance for recurrence 1

• Surgeons, radiologists, and pathologists should be vigilant in identifying, removing, and analyzing scalp SLNs due to their high rate of harboring metastatic disease 2