The relationship between histomorphological characteristics and Ki-67 proliferation index in meningiomas.

OBJECTIVES

This study had two aims. The first was to use the Ki 67 proliferation index (Ki-67 PI) to study the relationship between the proliferation potential and histopathological features such as mitosis, necrosis, loss of architecture, small cell change, hypercellularity, pleomorphism, brain invasion, dura invasion, bone invasion, and histological grade. The second aim was to compare primary and recurrent meningioma with respect to morphological characteristics and Ki-67 PI values.

BACKGROUND

Meningiomas are tumors whose histological features do not predict their biological behavior. Despite their slow growth and even after total resection, recurrence may occur

METHODS

A total of 245 meningioma cases in whom Ki-67 PI was studied were included in the study. The cases were assessed with respect to 10 morphological characteristics, and a possible significant relationship between these and Ki 67 PI was statistically tested.

RESULTS

We found a statistically significant relationship between Ki-67 PI and mitotic activity, necrosis, loss of architecture, small cell change, brain invasion. In contrast to brain invasion, no significant relationship was present between dura or bone invasion and Ki-67 PI. We identified asignificant increase in the histological grade, mitotic activity and Ki-67 PI value of recurrent tumors, as compared to primary ones

CONCLUSION

Ki-67 PI values overlap in different grades. This overlapping might be due to the heterogeneity of biological activity within the tumor tissue (Tab. 2, Fig. 7, Ref. 21).