ORIGINAL ARTICLE

Ultrarapid Ki-67 immunostaining in frozen section interpretation of gliomas

J Haapasalo¹, A Mennander², P Helen³, H Haapasalo and J Isola⁴

¹ University of Turku, Turku, FIN-20520, Finland
² Heart Centre, Tampere University Hospital, Tampere, Finland
³ Department of Neurosurgery, Tampere University Hospital
⁴ Institute of Medical Technology, University of Tampere, Tampere, FIN-33014, Finland

Correspondence to:
Correspondence to:
Dr H Haapasalo
Department of Pathology, Tampere University Hospital, PO Box 2000, FIN-33521 Tampere, Finland; hannu.haapasalo{at}pshp.fi

Background: Astrocytic tumours, the most common gliomas, are often classified intraoperatively using standard morphological staining. The final diagnosis and grading of gliomas on paraffin wax sections is often assisted by Ki-67 immunohistochemistry, but standard immunostaining protocols take too long to be used intraoperatively.

Aims: To investigate a new rapid Ki-67 immunohistochemical test for its use in an intraoperative setting.

Methods: The new Ki-67 immunostaining (Ultrarapid-Ki67®) method on frozen sections can be carried out in 10 minutes. Thirty four pilocytic and diffuse astrocytomas were immunostained by rapid Ki-67 and results were compared with corresponding MIB-1 staining, histological grading, and prognosis.

Results: The staining protocol was practical to perform and the results were morphologically and quantitatively indistinguishable from those after immunostaining with MIB-1, an antibody recognising Ki-67 in paraffin wax embedded tissue. A comparison of Ultrarapid-Ki67 and MIB-1 immunostaining of paraffin wax sections showed almost identical quantitative correlation in astrocytic gliomas (r = 0.916; p<0.001). The Ultrarapid-Ki67 indices (percentage of positive cells) of low grade (I/II) astrocytomas ranged from 0% to 6.1%, whereas those of representative high grade (III/IV) tumours were significantly higher (range, 5.6–45%; p<0.001). The best prognostic cutoff point for Ultrarapid-Ki67 was 7.5%, which divided diffuse grade II–IV astrocytomas into significantly differing subsets (p = 0.0008).

Conclusion: Ultrarapid-Ki67 immunostaining is a useful adjunct to morphological diagnosis and grading of astrocytic tumours, and as a fast test (10 minutes for staining plus three to four minutes for scoring), it could be used in routine intraoperative diagnosis of gliomas and other neoplastic diseases.

Abbreviations: DAB, diaminobenzidine; HE, haematoxylin and eosin; IHC, immunohistochemistry; ROC, receiver operating characteristics; WHO, World Health Organisation

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?