Epithelioid variant of gastrointestinal stromal tumor harboring PDGFRA mutation and MLH1 gene alteration: A case report.
Pathol Int
; 69(9): 541-546, 2019 Sep.
Article
en En
| MEDLINE
| ID: mdl-31273885
ABSTRACT
Gastrointestinal stromal tumors (GISTs) are the most important and common mesenchymal tumors of the gastrointestinal tract, especially in the stomach. GISTs are usually driven by activating mutations in either KIT or PDGFRA genes. It is known that activating gene mutations predicts, to a certain extent, not only the morphology of the tumor cells but also a response to treatment with tyrosine kinase inhibitors. Here, we present a case of an epithelioid variant of GIST harboring PDGFRA and MLH1 gene alterations in the stomach of a 55-year-old Japanese woman. The tumor of 98 mm with multiple cysts showed exophytic growth from the gastric fundus. Histopathologically, it consisted of scattered medium-sized epithelioid tumor cells in a loose myxoid background. Based on c-kit and DOG-1 immunoreactivity and a PDGFRA mutation (p.Trp559_Arg560del), the tumor was diagnosed as an epithelioid variant GIST. Interestingly, it had a gene alteration (p.Met524Ile) in the MLH1 gene of unknown pathogenicity. It was assigned to Group 3a (low risk for malignant behavior). After surgery, the patient has been on imatinib therapy and disease-free for 10 months.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Receptor alfa de Factor de Crecimiento Derivado de Plaquetas
/
Tumores del Estroma Gastrointestinal
/
Mesilato de Imatinib
/
Homólogo 1 de la Proteína MutL
/
Neoplasias Gastrointestinales
/
Antineoplásicos
Tipo de estudio:
Prognostic_studies
Límite:
Female
/
Humans
/
Middle aged
Idioma:
En
Revista:
Pathol Int
Asunto de la revista:
PATOLOGIA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Japón