Faculty Collaboration Database

Large cell/anaplastic medulloblastomas and medullomyoblastomas: clinicopathological and genetic features. J Neurosurg 2001 Jul;95(1):82-8

Date

07/17/2001

Pubmed ID

11453402

DOI

10.3171/jns.2001.95.1.0082

Scopus ID

2-s2.0-0034865073 (requires institutional sign-in at Scopus site)   92 Citations

Abstract

OBJECT: Medulloblastoma is the most common malignant central nervous system neoplasm found in children. A distinct variant designated large cell/anaplastic (LC/A) medulloblastoma is characterized by frequent dissemination of cerebrospinal fluid (CSF) at presentation and a more aggressive clinical course. The authors report on their examination of the clinicopathological and genetic features of seven such cases encountered at their institution.

METHODS: Eighty cases of medulloblastomas were reviewed and seven (8.8%) of these were believed to fit the histological and immunohistochemical criteria for LC/A medulloblastoma. In three cases (43%) either desmoplastic or classic medulloblastoma was the underlying subtype, and in two cases (28%) the LC/A tumor was found within the setting of medullomyoblastoma. Fluorescence in situ hybridization was used in six of the seven cases to characterize the presence of isochromosome 17q, deletion of chromosome 22q (a deletion characteristically found in atypical teratoid/rhabdoid tumors), and c-myc amplification. The patients' clinical histories revealed CSF dissemination in all cases and lymph node metastasis in one case. Isochromosome 17q was found in five (83%) of six cases. Evidence of chromosomal gains indicated aneuploidy in three tumors (50%), and amplification of c-myc was found in three tumors (50%). No 22q deletions were encountered.

CONCLUSIONS: A high percentage of LC/A medulloblastomas arise within a background of typical medulloblastomas or medullomyoblastomas. As is the case in conventional medulloblastomas, the presence of 17q is a common early tumorigenic event; however, in a significant percentage of specimens there is also evidence of aneuploidy and/or amplification of c-myc. These findings indicate that LC/A morphological characteristics reflect a more advanced tumor stage than that found in pure medulloblastomas or in typical medullomyoblastomas.

Author List

Leonard JR, Cai DX, Rivet DJ, Kaufman BA, Park TS, Levy BK, Perry A

Author

Bruce A. Kaufman MD Adjunct Professor in the Neurosurgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adolescent
Adult
Aneuploidy
Biomarkers, Tumor
Cerebellar Neoplasms
Cerebellum
Child
Chromosome Aberrations
Chromosome Deletion
Chromosome Mapping
Chromosomes, Human, Pair 22
Female
Gene Expression Regulation, Neoplastic
Humans
In Situ Hybridization, Fluorescence
Medulloblastoma
Prognosis
Proto-Oncogene Proteins c-myc