title: Epidermal growth factor receptor abnormalities in atypical teratoid/rhabdoid tumors and an unusual case with gene amplification.
abstract: Atypical teratoid/rhabdoid tumor (AT/RT) is a rhabdoid tumor of the central nervous system comprising a mixture of small round cells and mesenchymal and/or epithelial elements, showing mutation of the SMARCB1 gene or SMARCA4 gene. The epidermal growth factor receptor (EGFR) is one of the tyrosine kinase receptors whose overexpressed protein plays important roles in the malignant characteristics of various tumors. We analyzed 8 Japanese cases of AT/RT for EGFR protein overexpression and egfr gene amplification using immunohistochemistry and fluorescence in situ hybridization. The patients included 7 boys and 1 girl (age range 13 days to 2 years), and the tumors were localized in the frontal lobe (1 case), lateral ventricle (1 case), third ventricle (1 case), fourth ventricle (3 cases), and cerebellum (2 cases). We found that all (100%) of them partially expressed a high level of EGFR protein, and that one case showed amplification of egfr, the amplified area being localized and limited to a specific area within the tumor. We speculate that AT/RT is a tumor with heterogeneous egfr amplification, and that the frequency of amplification may depend on loss of function of the specific chromatin-remodeling member.
authors.affiliation: Department of Diagnostic Pathology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan. kaishis@md.tsukuba.ac.jp
authors.forename: Kaishi
authors.initials: K
authors.lastname: Satomi
authors.forename: Yukio
authors.initials: Y
authors.lastname: Morishita
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Murata
authors.forename: Aya
authors.initials: A
authors.lastname: Shiba-Ishii
authors.forename: Masato
authors.initials: M
authors.lastname: Sugano
authors.forename: Masayuki
authors.initials: M
authors.lastname: Noguchi
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics*; D001932:Brain Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000473:pathology; D002675:Child, Preschool; D066246:ErbB Receptors / Q000032:analysis / Q000235:genetics*; D005260:Female; D005784:Gene Amplification; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D008297:Male; D018335:Rhabdoid Tumor / Q000737:chemistry / Q000235:genetics* / Q000473:pathology; D013724:Teratoma / Q000737:chemistry / Q000235:genetics* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; C512478:EGFR protein, human; D066246:ErbB Receptors
keywords: Amplification; Atypical teratoid/rhabdoid tumor; EGFR; Fluorescence in situ hybridization; Immunohistochemistry