PRAME expression in melanocytic lesions of the conjunctiva.
Histopathology
; 79(6): 989-996, 2021 Dec.
Article
in En
| MEDLINE
| ID: mdl-34268800
ABSTRACT
AIMS:
PRAME (PReferentially expressed Antigen in MElanoma) is a tumour-associated antigen that is preferentially strongly expressed in most cutaneous melanomas but not or only focally in naevi. Our aim was to evaluate PRAME expression in melanocytic lesions of the conjunctiva. METHODS ANDRESULTS:
Surgical specimens of 114 conjunctival melanocytic naevi of different types (including 67 common, 25 combined deep penetrating and 21 inflamed juvenile naevi), 30 invasive melanomas, 10 in-situ melanomas, 23 primary acquired melanoses (PAM) without atypia and 11 PAM with atypia were analysed for PRAME expression by immunohistochemistry. Nuclear positivity for PRAME in melanocytes was assessed as the percentage of positive nuclei negative (0%), 1+ (1-25%), 2+ (26-50%), 3+ (51-75%) and 4+ (> 75%). In 113 of 114 conjunctival melanocytic naevi, PRAME was either completely negative or focally 1+ positive. Diffuse 4+ PRAME expression was identified in 17 of 30 (57%) invasive melanomas, seven of 10 (70%) in-situ melanomas, four of five (80%) PAM with severe atypia, none of three PAM with moderate atypia, none of three PAM with mild atypia, one of 23 (4%) PAM without atypia and none of 114 naevi. Diffuse 4+ PRAME expression in invasive melanomas correlated with a higher mitotic count but was not related to age and gender of the patients, Breslow thickness, location or mutational status.CONCLUSION:
Diffuse 4+ PRAME positivity is highly specific for malignant conjunctival melanocytic lesions. PRAME is therefore a useful ancillary marker to support the diagnosis of a suspected conjunctival melanoma.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Conjunctival Neoplasms
/
Melanoma
/
Antigens, Neoplasm
Type of study:
Prognostic_studies
Limits:
Adolescent
/
Adult
/
Aged
/
Aged80
/
Child
/
Child, preschool
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Histopathology
Year:
2021
Document type:
Article
Affiliation country:
Eslovenia
Publication country:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
/
UK
/
UNITED KINGDOM