BRAFV600E mutations and immunohistochemical expression of VE1 protein in low-grade serous neoplasms of the ovary.
Histopathology
; 73(3): 438-443, 2018 Sep.
Article
en En
| MEDLINE
| ID: mdl-29770477
ABSTRACT
AIMS:
The most common BRAF mutation in ovarian low-grade serous neoplasms (LGSNs) involves substitution of valine by glutamic acid at position 600 (V600E). Small studies have demonstrated high specificity of immunohistochemistry with mutation-specific monoclonal antibody VE1. We sought to investigate the expression of VE1 protein in LGSNs and its correlation with BRAF mutation-associated histological features and BRAF mutation status. METHODS ANDRESULTS:
We reviewed pathology reports and available slides from ovarian serous borderline tumours (SBTs) and low-grade serous carcinomas (LGSCs) diagnosed between 2000 and 2012. VE1 immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissue sections. Tumours with ≥50% positive cells were considered positive. Of 121 LGSNs, there were 73 SBTs, eight SBTs with micropapillary features (mpSBT) and 40 LGSCs (22 primary, 18 metastatic). VE1 was positive in 52% (38 of 73) of SBTs and 9% (two of 22) of primary LGSCs, and in none of the mpSBTs and metastatic LGSCs (P < 0.0001). Of 76 tumours with known mutation status, 42 (55%) harboured mutations, including BRAFV600E (26, 34%), KRASG12D (eight, 11%), and KRASG12V (eight, 11%). BRAFV600E mutations were present in 48% (25 of 52) of SBTs and 5% (one of 22) of LGSCs (P < 0.0001). VE1 was positive in 96% (25 of 26) of BRAFV600E -mutated tumours and correlated with BRAF mutation-associated histological features (P < 0.0001).CONCLUSIONS:
BRAFV600E mutations are significantly more common in SBTs than in LGSCs. Immunohistochemical expression of VE1 protein is associated strongly with BRAFV600E mutation and BRAF mutation-associated histological features. VE1 immunohistochemistry is a reliable method for the detection of BRAFV600E mutations.Palabras clave
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Bases de datos:
MEDLINE
Asunto principal:
Neoplasias Ováricas
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Cistadenocarcinoma Seroso
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Proteínas Proto-Oncogénicas B-raf
Límite:
Adult
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Female
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Humans
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Middle aged
Idioma:
En
Revista:
Histopathology
Año:
2018
Tipo del documento:
Article
País de afiliación:
Estados Unidos