A novel case of endometrial dedifferentiated adenocarcinoma associated with MLH1 promotor hypermethylation and microsatellite instability.
Pathol Res Pract
; 214(11): 1904-1908, 2018 Nov.
Article
em En
| MEDLINE
| ID: mdl-30173944
ABSTRACT
Endometrial dedifferentiated carcinoma is a rare, malignant tumor whose molecular alterations have not been clarified yet. We report a novel case of a 61-year old woman who presented with irregular vaginal bleeding after menopause and a 3 cm uterus mass. Histology revealed endometrial dedifferentiated adenocarcinoma, a rare subtype comprised of undifferentiated adenocarcinoma. The patient still survived 1 year after surgery without chemotherapy and radiotherapy. Immunohistochemistry revealed loss of MLH1/PMS2 expression and retained MSH2/MSH6 expression. Consistently, microsatellite instability was detected indicative of high microsatellite instability (MSI-H). No BRAF V600E, KRAS and POLE mutations were identified. Remarkably, the promoter regions of mutL homolog 1(MLH1) were methylated. Furthermore, several tumor cells were PD-L1 positive in this case with a concentration at the infiltrating tumor edge indicating MSI-H in endometrial dedifferentiated adenocarcinoma is a potential predictive factor for response to immunotherapy targeting the PD-1 or its ligand PD-L1.
Palavras-chave
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Adenocarcinoma
/
Neoplasias do Endométrio
/
Proteína 1 Homóloga a MutL
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Limite:
Female
/
Humans
/
Middle aged
Idioma:
En
Revista:
Pathol Res Pract
Ano de publicação:
2018
Tipo de documento:
Article