LAB INVESTIGATION-HUMAN/ANIMAL TISSUE

EGFR immunolabeling pattern may discriminate low-grade gliomas from gliosis

Fanny Burel-Vandenbos?Maxime Benchetrit?Catherine Miquel?

Denys Fontaine?Romane Auvergne?Christine Lebrun-Frenay?Nathalie Cardot-Leccia?Jean-Franc?ois Michiels?Veronique Paquis-Flucklinger?Thierry Virolle

Received:21September2007/Accepted:8July2010

óSpringer Science+Business Media,LLC.2010

Abstract Overexpression of epidermal growth factor receptor(EGFR)is common in gliomas.Gliomas are in?ltrating tumors in which neoplastic glial cells can be intermingled with reactive glial cells,particularly in diffuse low-grade gliomas.As overexpression of EGFR has also been described in gliosis,it can be dif?cult to evaluate EGFR immunolabeling in diffuse low-grade gliomas because of this cell mix.We compared EGFR immunola-beling between gliosis and low-grade gliomas in order to identify distinctive criteria.We studied EGFR expression in28cases of gliosis and39diffuse low-grade gliomas(23 astrocytomas and16oligodendrogliomas).EGFR immu-nohistochemistry staining was performed on paraf?n-embedded sections with a mouse monoclonal antibody (clone2-18C9;Dako).Co-expression of EGFR with Olig2, Mib-1,and p53was assessed in seven cases of low-grade gliomas using double immunolabeling.Then,EGFR immunostaining was blindly tested on22small specimens of indeterminate glial lesions provided by a reference neuropathological center.Two pathologists of our local center were asked to classify the lesions into diffuse low-grade glioma or gliosis according to the pattern of EGFR expression.Weak expression of EGFR was commonly detected in gliosis(23/28cases).Strongly-stained cells were absent.Positive cells had reactive glial cell mor-phology.EGFR expression in gliomas was characterized by constant strongly-stained cells(39/39cases).All strongly-stained cells had a high nucleus-to-cytoplasm ratio,with minimal to moderate nuclear atypia.Most of the strongly EGFR-positive cells were Olig2-positive.All the cases displayed cells co-expressing EGFR and Mib-1.In three p53-positive tumors,many p53-positive cells were strongly EGFR-positive.On the basis of EGFR expression, 14out of the22indeterminate cases were classi?ed as

Veronique Paquis-Flucklinger and Thierry Virolle contributed equally to this work.

F.Burel-VandenbosáM.BenchetritáR.Auvergneá

N.Cardot-LecciaáJ.-F.Michiels

Department of Pathology,University Hospital of Nice,Nice, France

C.Miquel

Department of Pathology-Neuro-oncology,Sainte-Anne Hospital and Faculte′CochinPort-Royal,University Paris V, Paris,France

D.Fontaine

Department of Neurosurgery,University Hospital of Nice,Nice, France

C.Lebrun-Frenay

Department of Neurology,University Hospital of Nice,Nice, France V.Paquis-Flucklinger

Department of Genetics,University Hospital of Nice,Nice, France

F.Burel-VandenbosáT.Virolle

INSERM U898/UNSA Stem Cells,Cancer and Development, Faculty of Medicine,Universite′de Nice Sophia-Antipolis,Nice, France

F.Burel-Vandenbos(&)

Laboratoire Central d’Anatomie Pathologique,Hopital Pasteur, 30avenue de la Voie Romaine,06000Nice,France

e-mail:burel-vandenbos.f@chu-nice.fr

J Neurooncol

DOI10.1007/s11060-010-0308-4