title: Sentinel lymph node biopsy in patients with thin primary cutaneous melanoma.
abstract: OBJECTIVE
  To determine the rate and clinicopathologic factors predictive of sentinel lymph node (SLN) positivity, regional lymph node recurrence, and survival in a large series of patients with thin primary cutaneous melanoma who underwent SLN biopsy (SLNB).
  
  
  METHODS
  Patients with thin (≤1 mm) melanomas who underwent SLNB between 1992 and 2009 at Melanoma Institute Australia were identified from the Melanoma Institute Australia database. The association of clinicopathologic features with SLN status, lymph node recurrence, and survival was analyzed.
  
  
  RESULTS
  In 432 patients [226 men, 206 women; median age 49.5 years (range: 14.4-85.0 years)], SLNB was positive for metastatic melanoma in 29 (6.7%) patients. No SLN positivity was detected in 37 patients with primary tumor thickness 0.50 mm or less. Breslow thickness (P = 0.012) and presence of lymphovascular invasion (P = 0.018) were the only factors significantly associated with SLN positivity. Regional lymph node recurrence was significantly more common in tumors located in the head/neck region (4/33, 12%) than in extremities (3/245, 1.2%) and trunk (2/154, 1.3%) (P < 0.001). Primary tumor mitotic rate was a significant predictor of melanoma-specific survival (Hazard Ratio [HR] = 1.2, 95% confidence interval: 1.09-1.35, P < 0.001).
  
  
  CONCLUSIONS
  There is a low but significant rate of SLN positivity in patients with primary melanomas 0.51 to 1.0 mm in thickness. Given its prognostic importance, SLNB should be considered in such patients, particularly if there is lymphatic permeation by melanoma at the primary tumor site. More frequent regional node field recurrences in patients with head/neck primary tumors may be a consequence of complex lymphatic drainage patterns in this region.
authors.affiliation: Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia. MuraliR@mskcc.org
authors.forename: Rajmohan
authors.initials: R
authors.lastname: Murali
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Haydu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Quinn
authors.forename: Robyn P M
authors.initials: RP
authors.lastname: Saw
authors.forename: Kerwin
authors.initials: K
authors.lastname: Shannon
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Spillane
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Stretch
authors.forename: John F
authors.initials: JF
authors.lastname: Thompson
authors.forename: Richard A
authors.initials: RA
authors.lastname: Scolyer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008545:Melanoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology; D011379:Prognosis; D016016:Proportional Hazards Models; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D055815:Young Adult