Proliferative activity of meningiomas as evaluated by bromodeoxyuridine uptake examination.

Proliferative activity of meningiomas was examined in 12 consecutive cases by administering bromodeoxyuridine (BrdU) before surgical removal and by immunohistochemical staining of the removed tumours using anti-BrdU monoclonal antibody (anti-BrdU MAb) to detect BrdU-labelled tumour cells. The 12 cases consisted of 6 with a primary tumour and 6 with a recurrent tumour. All of the tumours contained labelled cells and the labelling index (LI) was obtained in each tumour. The highest average LI was 13.6% and the second highest was 9.0% both in recurrent cases of histologically malignant meningothelial meningioma. The high LIs of both cases were thought to correspond well with the rapid recurrence of the tumour. The average LI of a case of recurrent haemangiopericytic tumour was 2.0%, and that of a case of meningioma associated with von Recklinghausen disease was 1.5%. The other 8 meningiomas showed the average LIs ranging from 0.1 to 0.9%, which were considered to be the LIs of usual benign meningiomas. The results of the BrdU uptake examination was considered to reflect well the clinical behaviour of meningiomas. The usefulness of the BrdU uptake examination in brain tumours, which can be employed in the clinical practice without any serious side-effects, is stressed.