Immunohistochemical and molecular analysis of spitzoid neoplasms with pulverocyte subclones.
Clin Exp Dermatol
; 43(7): 782-789, 2018 Oct.
Article
in En
| MEDLINE
| ID: mdl-29779219
ABSTRACT
BACKGROUND:
Clonal naevi are characterized by a focal proliferation of pigmented melanocytes in an otherwise banal naevus. These subclones are often composed of aggregates of larger, epithelioid melanocytes with nuclear atypia and dusty-grey cytoplasmic pigmentation, which are referred to as 'pulverocytes', and this finding may lead to a misdiagnosis of malignant melanoma (MM).AIM:
To characterize the significance of subclones of dusty-grey pigmented epithelioid melanocytes within spitzoid neoplasms.METHODS:
We studied the histological and molecular features of a series of 20 spitzoid neoplasms with pulverocyte subclones encountered in our practice, including both atypical Spitz tumours (ASTs) and invasive MMs.RESULTS:
Pulverocytes were predominantly dermal, and the percentage of subclones ranged from 2% to 40%, with a median of 10% in ASTs and 25% in lesions we classified as MM. In cases with > 10% subclones, there was an increased odds of fluorescence in situ hybridization positivity (OR = 12; 95% CI 1.2-293.4; P = 0.03) and an increased odds of homozygous 9p21 deletion (OR = 3.6; 95 CI 0.28-89.82; P = 0.33), although the latter did not reach statistical significance.CONCLUSIONS:
We consider spitzoid lesions with a small subclone population to be a variant of a clonal naevus with indolent behaviour, whereas lesions with larger pulverocyte populations are more likely to have chromosomal copy number aberrations and in some cases may represent malignant transformation.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Skin Neoplasms
/
Melanocytes
/
Melanoma
/
Nevus, Pigmented
Type of study:
Observational_studies
Limits:
Adolescent
/
Adult
/
Aged
/
Child
/
Child, preschool
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Clin Exp Dermatol
Year:
2018
Document type:
Article
Affiliation country:
Estados Unidos