title: The unpredictability of lymphatic drainage from the ear in melanoma patients, and its implications for management.
abstract: BACKGROUND
  The ear is known to have variable lymphatic drainage. The purpose of this study was to define better the lymphatic drainage patterns of the ear by correlating the location of primary tumors, classified according to the embryologically derived anatomical subunits of the ear, with their mapped sentinel nodes (SNs) identified by lymphoscintigraphy (LS).
  
  
  METHODS
  Lymphatic drainage data for patients with a primary melanoma of the ear were reviewed and correlated with the precise primary melanoma site.
  
  
  RESULTS
  Between 1993 and 2010, LS was performed in 111 patients with a primary melanoma on the ear, identifying 281 SNs in 195 lymph node (LN) fields. The mean numbers of SNs and LN fields identified by LS per patient were 2.65 and 1.76. SN biopsy was performed in 71 patients (64 %). The mean number of SNs removed was 2.36. The 111 ear melanomas were mostly located on the helical rim (55 %), followed by the lobule (24.3 %). The five different primary ear sites drained mainly to SNs in level CII, level CV and the preauricular region. Drainage was most often to level CII (36.4 %). Drainage to the contralateral neck was not observed.
  
  
  CONCLUSIONS
  Lymphatic drainage of the ear has no predictable pattern and can be to SNs anywhere in the ipsilateral neck. Most commonly drainage is to cervical level II and the preauricular and postauricular LN fields. LS defines the lymphatic drainage pattern in individual melanoma patients and is essential for accurate SN identification and reliable SN biopsy.
authors.affiliation: Melanoma Institute Australia, North Sydney, NSW, Australia.
authors.forename: Howard S
authors.initials: HS
authors.lastname: Peach
authors.forename: Augustinus P T
authors.initials: AP
authors.lastname: van der Ploeg
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Haydu
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Stretch
authors.forename: Kerwin F
authors.initials: KF
authors.lastname: Shannon
authors.forename: Roger F
authors.initials: RF
authors.lastname: Uren
authors.forename: John F
authors.initials: JF
authors.lastname: Thompson
mesh_terms: D054644:Ear Auricle / Q000196:embryology / Q000473:pathology*; D004428:Ear Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D061305:Lymphoscintigraphy; D008297:Male; D008545:Melanoma / Q000556:secondary* / Q000601:surgery; D008875:Middle Aged; D037981:Neck Dissection; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery