Prediction of sentinel lymph node micrometastasis by histological features in primary cutaneous malignant melanoma.
OBJECTIVE
To develop a prognostic model, based on clinical and pathological data, to estimate the probability of micrometastasis in the sentinel lymph node in patients with malignant melanoma.


METHODS
Retrospective analytical study.


METHODS
University medical center.


METHODS
Two hundred fifteen patients with American Joint Committee on Cancer stages I and II cutaneous malignant melanoma underwent sentinel lymph node biopsy.


METHODS
Presence of microscopic melanoma in the sentinel lymph node(s). Clinical attributes recorded included age, sex, and location of the primary melanoma. Pathological attributes recorded before lymph node evaluation included ulceration, microsatellites, angiolymphatic invasion, mitotic rate, tumor infiltrating lymphocytes, and regression.


RESULTS
Forty-six patients (21.4%) overall had a positive sentinel lymph node. Patients with tumor thickness ranging from 3.0 to 3.9 mm had the highest incidence (50%) of nodal involvement, followed by those with tumors 4.0 to 4.9 mm thick (41%). Patients with melanomas measuring greater than 4.9 mm thick and those between 1.0 and 2.9 mm had a similar rate of nodal involvement (16%-17%). Clinical characteristics had minimal correlation with nodal status in multivariate analysis. The total number of histological high-risk features was significantly correlated with sentinel lymph node involvement. Important pathological risk factors included ulceration, high mitotic rate, angiolymphatic invasion, and microsatellites. Patients with tumor thickness greater than 1.0 mm but lacking these features had a 14% risk of occult metastases.


CONCLUSIONS
Among patients with clinically node-negative primary melanoma, the presence of 1 or more high-risk histological features significantly increases the incidence of microscopic nodal involvement and can be used to predict the likelihood of a positive sentinel lymph node biopsy.
Department of Dermatology, University of California/Mount Zion Medical Center, San Francisco, USA.
S
S
Mraz-Gernhard
R W
RW
Sagebiel
M
M
Kashani-Sabet
J R
JR
Miller
S P
SP
Leong
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005260:Female; D005544:Forecasting; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology*; D008208:Lymphatic System / Q000473:pathology; D016246:Lymphocytes, Tumor-Infiltrating / Q000473:pathology; D008297:Male; D008545:Melanoma / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D018895:Microsatellite Repeats; D008875:Middle Aged; D008938:Mitosis; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011336:Probability; D011379:Prognosis; D012074:Remission Induction; D012189:Retrospective Studies; D012307:Risk Factors; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery; D014456:Ulcer / Q000473:pathology