Genetic and morphologic features for melanoma classification.
Melanoma is comprised of biologically distinct subtypes. The defining clinical, histomorphologic, and molecular features are not fully established. This study sought to validate the association between genetic and histomorphologic features previously described and to determine their reproducibility and association with important clinical variables. Detailed clinical and histomorphologic features of 365 primary cutaneous melanomas were assessed by 11 pathologists and correlated with mutation status of BRAF and NRAS. There was substantial agreement in the quantitative assessment of histomorphologic features showing similar or better interobserver reproducibility than the established World Health Organization classification scheme. We confirmed that melanomas with BRAF mutations showed characteristic morphologic features (P < 0.0001) and metastasized more frequently to regional lymph nodes (P = 0.046). Importantly, melanomas without mutations were a heterogeneous group, with a subset having very similar clinical and morphological features as those with BRAF mutation raising the possibility that they are biologically related. Our study confirms an association between histomorphologic features, mutation status, and pattern of metastasis, providing criteria for a refined melanoma classification aimed at defining biologically homogeneous disease subgroups.
Broekaert
Sigrid M C
SM
Department of Dermatology, University of California San Francisco, 1701 Divisadero St, San Francisco, CA 94115, USA.
Roy
Ritu
R
Okamoto
Ichiro
I
van den Oord
Joost
J
Bauer
Jürgen
J
Garbe
Claus
C
Barnhill
Raymond L
RL
Busam
Klaus J
KJ
Cochran
Alistair J
AJ
Cook
Martin G
MG
Elder
David E
DE
McCarthy
Stanley W
SW
Mihm
Martin C
MC
Schadendorf
Dirk
D
Scolyer
Richard A
RA
Spatz
Alan
A
Bastian
Boris C
BC
D000368:Aged; D000465:Algorithms; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000145:classification* / Q000235:genetics* / Q000473:pathology; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D009362:Neoplasm Metastasis / Q000235:genetics; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D014944:World Health Organization
C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf