MIB-1 counting methods in meningiomas and agreement among pathologists.
OBJECTIVE
To evaluate the correlation of MIB-1 labeling index (LI) obtained by 2 counting methods with histologic grade and investigate interobserver variability between these methods.


METHODS
A total of 65 meningiomas were analyzed for proliferation with 2 counting methods by 2 pathologists using MIB-1 antibody. In the first method, the most densely staining areas were counted (HL method). In the second method, randomly selected areas were counted (RS method).


RESULTS
MIB-1 values correlated well with histologic grade in both methods. As expected, the tumors with recurrence had significantly higher LIs than the nonrecurrent tumors in each method. However, there was a statistically significant difference in the mean MIB-1 values of between the HL and RS methods. When MIB-1 LI was compared between 2 pathologists, perfect agreement in the HL method and substantial agreement in the RS method were achieved.


CONCLUSIONS
Our results showed that values of MIB LIs differ with different counting methods. Nonetheless, both methods showed good correlation with World Health Organization grades. Therefore standardization of 1 counting method is of great importance for determining a reliable and specific cutoff value in assessing the risk of recurrence in meningiomas.
Rezanko
Turkan
T
Department of Pathology, Izmir Ataturk Education and Research Hospital, Izmir, Turkey. rezankoa@yahoo.com
Akkalp
Asli Kahraman
AK
Tunakan
Mine
M
Sari
Aysegul Akder
AA
D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis*; D008577:Meningeal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008579:Meningioma / Q000175:diagnosis* / Q000473:pathology; D009364:Neoplasm Recurrence, Local; D015588:Observer Variation; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; D019394:Ki-67 Antigen; C440408:MIB-1 antibody