A new subtype of high-grade mandibular osteosarcoma with RASAL1/MDM2 amplification.
Hum Pathol
; 50: 70-8, 2016 Apr.
Article
en En
| MEDLINE
| ID: mdl-26997440
ABSTRACT
In contrast to long bone osteosarcoma, mandibular osteosarcoma is highly heterogeneous and morphologically overlaps with benign tumors, obscuring diagnosis and treatment selection. Molecular characterization is difficult due to the paucity of available specimens of this rare disease. We aimed to characterize the spectrum of mandibular osteosarcoma using immunohistochemistry and molecular techniques (quantitative polymerase chain reaction and sequencing) and compare them with benign fibro-osseous lesions. Forty-nine paraffin-embedded mandible osteosarcoma tissue samples were collected retrospectively and compared with 10 fibrous dysplasia and 15 ossifying fibroma cases. These were analyzed for molecular markers thought to differ between the different diseases and subtypes MDM2 (murine double-minute type 2) overexpression, GNAS (guanine nucleotide-binding protein/α subunit) mutations, and amplification of MDM2 and/or RASAL1 (RAS protein activator like 1). Five fibroblastic high-grade osteosarcoma subtypes showed MDM2 amplification, including 2 with a microscopic appearance of high-grade osteosarcoma with part low-grade osteosarcoma (differentiated/dedifferentiated osteosarcoma) and MDM2 overexpression. The other 3 contained a coamplification of MDM2 and RASAL1, a signature also described for juvenile ossifying fibroma, with no overexpression of MDM2. These were of the giant cell-rich high-grade osteosarcoma, with areas mimicking juvenile ossifying fibroma (ossifying fibroma-like osteosarcoma). Our results show that some diagnosed high-grade osteosarcomas are differentiated/dedifferentiated osteosarcomas and harbor an overexpression and amplification of MDM2. In addition, juvenile ossifying fibromas can potentially evolve into giant cell-rich high-grade osteosarcomas and are characterized by a RASAL1 amplification (osteosarcoma with juvenile ossifying fibroma-like genotype). Thus, the presence of a RASAL1 amplification in ossifying fibroma may indicate a requirement for closer follow-up and more aggressive management.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Neoplasias Mandibulares
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Biomarcadores de Tumor
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Osteosarcoma
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Amplificación de Genes
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Proteínas Activadoras de GTPasa
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Proteínas Proto-Oncogénicas c-mdm2
Tipo de estudio:
Observational_studies
/
Prognostic_studies
Límite:
Adolescent
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Adult
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Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Hum Pathol
Asunto de la revista:
PATOLOGIA
Año:
2016
Tipo del documento:
Article
País de afiliación:
Francia