CC BY-NC-ND 4.0 · Indian Journal of Neurosurgery 2018; 07(02): 129-134
DOI: 10.1055/s-0038-1668469
Original Article
Thieme Medical and Scientific Publishers Private Ltd.

Study of Histomolecular Classification of Glioma-Integrating Histology and Molecular Analysis in the Diagnosis of Brain Tumors

Shameen Yumnam Devi
1  Department of Histopathology, Apollo Hospital, Hyderabad, Telangana, India
,
Michelle De Padua
2  Department of Pathology, Apollo Hospitals, Hyderabad, Telangana, India
,
Iravathy Goud Kalal
3  Division of Human Genetics, Department of Molecular Biology and Cytogenetics, Apollo Hospitals, Hyderabad, Telangana, India
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Publikationsverlauf

Received: 07. Dezember 2017

accepted after revision: 16. April 2018

Publikationsdatum:
10. August 2018 (online)

  

Abstract

Introduction The updated 2016 classification of gliomas incorporates well-established molecular parameters into the classification of diffuse gliomas, taking into account isocitrate dehydrogenase 1 (IDH1) mutation, α-thalassemia/mental retardation syndrome X-linked (ATRX) loss, and 1p/19q co-deletion.

Aim and Objectives To study IDH1 and ATRX mutations in gliomas, 1p/19q co-deletion by fluorescent in situ hybridization (FISH) in oligodendroglioma, and to correlate IDH1, ATRX, and 1p/19q with tumor type and grade.

Material and Methods Total 73 cases of gliomas were diagnosed on histology and graded as astrocytoma (grades 2–4), oligodendroglioma (grades 2–3), and oligoastrocytoma (grades 2–3) by two pathologists independently. IDH mutation and ATRX expression were analyzed using immunohistochemistry in all cases whereas 1p/19q co-deletion was studied using FISH in cases with oligodendroglioma and oligoastrocytoma morphology.

Results Total 48 cases of astrocytoma, 9 cases of oligoastrocytoma, and 16 cases of oligodendroglioma were included. The maximum number of IDH1 mutation cases were seen in diffuse astrocytoma (7/10; 70%) as compared with anaplastic astrocytoma (5/15; 33.33%), glioblastoma multiforme (GBM) (3/23; 13.04%) grade II oligoastrocytoma (3/6; 50%), anaplastic oligoastrocytoma (2/3; 66.67%), and oligodendroglioma grade II (7/10; 70%). ATRX loss was seen in diffuse astrocytoma grade II (6/10; 60%), anaplastic astrocytoma (6/15; 40%), oligoastrocytoma grade II (2/6; 33.33%), and anaplastic oligoastrocytoma (1/3; 33.33%). 1p/19q co-deletion was seen in oligoastrocytoma (2/2; 100%), anaplastic oligoastrocytoma (1/2; 50%), oligodendroglioma (3/4; 75%), and anaplastic oligodendroglioma (1/3; 33.33%). Six of the seven cases with 1p/19q co-deletion also showed IDH1 mutation. One of seven 1p/19q co-deleted cases had loss of expression of ATRX.

Conclusion Incorporation of IDH1 mutation, ATRX loss, and 1p/19q co-deletion molecular studies help in a more accurate diagnosis and classification of gliomas.