Minim Invasive Neurosurg 2008; 51(5): 275-279
DOI: 10.1055/s-0028-1082322
Original Article

© Georg Thieme Verlag KG Stuttgart · New York

Low-Grade Glioma on Stereotactic Biopsy: How Often is the Diagnosis Accurate?

Y. Muragaki 1 , 2 , M. Chernov 3 , T. Maruyama 1 , T. Ochiai 1 , T. Taira 1 , O. Kubo 1 , R. Nakamura 2 , 3 , H. Iseki 1 , 2 , 3 , T. Hori 1 , K. Takakura 1 , 2 , 3
  • 1Department of Neurosurgery, Neurological Institute, Tokyo Women’s Medical University, Tokyo, Japan
  • 2Faculty of Advanced Techno-Surgery, Institute of Advanced Biomedical Engineering and Science, Tokyo Women’s Medical University, Tokyo, Japan
  • 3International Research and Educational Institute for Integrated Medical Sciences (IREIIMS), Tokyo Women’s Medical University, Tokyo, Japan
Further Information

Publication History

Publication Date:
14 October 2008 (online)

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Abstract

The objective of the present study was an evaluation of the incidence and risk factors for erroneous histopathological diagnosis of low-grade glioma after stereotactic biopsy. Twenty-eight tumors diagnosed as low-grade glioma after stereotactic biopsy and surgically resected thereafter were analyzed. There were 13 astrocytomas, 7 oligodendrogliomas, and 8 mixed gliomas. All neoplasms had a lobar location. Seven tumors had contrast enhancement on MRI. The number of tissue samples obtained during stereotactic biopsy was one in 19 cases, two in 4, and three or more in 5. Complete diagnostic agreement in tumor typing and grading after stereotactic biopsy and surgical resection was attained in 10 cases (36%). Agreement in tumor typing was marked in 16 cases (57%). Erroneous typing was more frequent in tumors with an MIB-1 index of less than 3% (P=0.0629) and mixed gliomas (P=0.0801). Overgrading of WHO grade I tumors was marked in 3 cases (11%) and undergrading of WHO grade III gliomas in 8 cases (28%). Tumor undergrading was more frequent in cases with an MIB-1 index of more than 3% (P=0.0045). The MIB-1 index detected after stereotactic biopsy was nearly always lower compared with those established after surgical resection (P<0.0001). In conclusion, the histopathological diagnosis of low-grade glioma established after stereotactic biopsy is associated with a substantial risk of inaccuracy. Tumors with low proliferative activity and mixed gliomas are especially susceptible for erroneous tumor typing. Undergrading of high-grade gliomas may be suspected if the MIB-1 index in the tumor specimen constitutes more, than 3%.

References

Correspondence

Y. MuragakiMD, PhD 

Faculty of Advanced Techno-Surgery

Institute of Advanced Biomedical Engineering and Science

Graduate School of Medicine

Tokyo Women’s Medical University

8-1 Kawada-cho

Shinjuku-ku

Tokyo 162-8666

Japan

Phone: +81/3/3353 81 11 ext.399 89

Fax: +81/3/5361 77 96

Email: ymuragaki@abmes.twmu.ac.jp