Sentinel node staging of primary melanoma by the "10% rule": pathology and clinical outcomes.
BACKGROUND
Surgical staging of clinically node-negative primary melanoma involves identification and removal of "sentinel" lymph nodes (SLNs). Although some suggest removal of only the "hottest" SLN, the "10% rule" dictates that nodes are removed until the background count is 10% or less of the count of the "hottest" node.


METHODS
To determine the utility of the 10% rule, a university database of clinically node-negative melanomas surgically staged by using this rule was examined.


RESULTS
Twenty-two of 177 cases (12.5%; 15% of T2 and T3 lesions) were SLN positive. Among the SLN-positive cases, use of the rule resulted in removal of 21 additional nodes, 7 of which contained tumor. In 3 cases (14%), the positive SLN was not the "hottest" node. At 49 months of mean follow-up time, overall survival was 63% for SLN-positive patients versus 92% for SLN-negative patients (P = .01).


CONCLUSIONS
Sentinel node staging of melanoma by the 10% rule provides significant prognostic information and a modest increase in tumor detection compared with removal of only the "hottest" node.
Emery
Rachel E
RE
School of Medicine, L109 Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
Stevens
Jeffery S
JS
Nance
Robert W
RW
Corless
Christopher L
CL
Vetto
John T
JT
D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000473:pathology* / Q000601:surgery*; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery*; D016896:Treatment Outcome