SKIN 
 

March 2019     Volume 3  Issue 2 
 

Copyright 2018 The National Society for Cutaneous Medicine 126 

RISING DERM STARS® 
 

 
De novo versus nevus-associated melanomas: differences in associations 
with prognostic indicators and survival 
 
Rachel Cymerman, MD, MS1, Yongzhao Shao, Kun Wang, Yilong Zhang, Era C. Murzaku, Lauren 
A. Penn, Iman Osman, David Polsky 
 
1Department of Dermatology, New York University, New York, NY 

 
 
Background/Objectives: Although 20%-
30% of melanomas are histopathologically 
‘nevus-associated’, the majority of 
melanomas arise de novo, i.e. in clinically 
normal skin with no associated nevus. We 
examined whether these forms of melanoma 
differed in their associations with clinical and 
histopathologic features, and patient survival. 
 
Methods: We analyzed 2 prospective 
cohorts from our institution with protocol–
driven follow up information (NYU1, n=1048; 
NYU2, n=1202).  We used univariate and 
multivariate analyses to examine 
associations between de novo versus nevus-
associated melanoma classification and age, 
anatomic site, tumor thickness, tumor 
ulceration, mitotic index, histological subtype, 
clinical stage, and survival.   We tested the 
associations identified in NYU1 using NYU2 
as a replication cohort.   
 
Results: In NYU1, de novo melanomas were 
associated with tumor thickness > 1.0mm 
(p<0.0001), ulceration (p=.024), nodular 
subtype (p=.009), stage > 1 (p<0.0001), older 
age (p<0.0001), and shorter overall survival 
(p=.0007).   In NYU2, de novo melanoma was 
again significantly associated with tumor 
thickness > 1.0mm (p<0.0001), ulceration 
(p<0.0001), nodular subtype (p<0.0001), 
stage > 1 (p<0.0001), older age (p<0.0001), 

and shorter overall survival (p<0.0001). In 
multivariate analysis, de novo classification 
was an independent, poor prognostic 
indicator. Male patients had a statistically 
significantly worse survival than female 
patients if their melanoma was de novo 
(NYU1, p<0.0001; NYU2, p=0.0004); 
unexpectedly, there was no gender 
difference in survival among patients with 
nevus-associated tumors. 
 
Conclusion: These data suggest that de 
novo melanomas are more aggressive than 
nevus-associated melanomas.  This 
classification scheme may also provide a 
useful framework for investigations into 
gender differences in melanoma outcomes.  
Recognizing these trends may have 
implications for screening.