Dermal lymphatics

Reticular dermis · Sentinel node Lymphoedema No epidermal lymphatics

Blind-ended initial lymphatics beginning in the papillary dermis and draining into a deeper dermal and subcutaneous plexus. They clear interstitial fluid and protein and carry antigen-loaded dendritic cells to the regional node.

Traced from the start

  1. Stratum basale (germinativum)
  2. Lamina densa (type IV collagen basement membrane)Sublamina densa anchoring fibrils (type VII collagen)
  3. Papillary dermis
  4. Dermal lymphatics

Detail

Origin
Blind-ended, valveless initial lymphatics in the papillary dermis; the epidermis itself has none
Function
Return interstitial protein and fluid, and provide the migration route for Langerhans and dermal dendritic cells to the draining lymph node
Surgical relevance
Cutaneous lymphatic drainage is predictable enough that lymphoscintigraphy plus blue dye identifies the sentinel node in melanoma and breast cancer

When it goes wrong

Streptococcal cellulitis or erysipelas scarring the dermal lymphatics

Impaired drainage predisposes to further attacks, setting up a cycle of recurrent cellulitis and progressive lymphoedema that may need long-term prophylactic penicillin

Chronic lymphoedema of any cause

Non-pitting swelling with a positive Stemmer sign, skin thickening, and a small long-term risk of lymphangiosarcoma; management is compression and skin care, not diuretics

Practise this structure

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