Outcome of 31 intracranial haemangiopericytomas: Poor predictive value of cell proliferation indices

Cell proliferation indices of 31 primary intracranial haemangiopericytomas (HPC) and their recurrences and metastases were correlated with the long-term recurrence, metastasis and survival rates. Paraffin-embedded specimens were used for K-67, PCNA and p53 immunostainings and for estimation of S-phase fraction (S-PF) in flow cytometry. The median Ki-67 and PCNA indices and S-PFs were 10.4, 3.2, and 4.0 for primary HPCs and 14.1, 14.1, and 5.5 for recurrences, respectively. High indices were associated with higher recurrence, metastasis and death rates, but not at the p ≤ 0.5 level. Consequently, these indices do not seem useful in planning of treatment and follow-up of meningeal HPCs. Meningeal HPCs, in contrast to meningiomas, recur almost always despite seemingly complete removal and often metastasize elsewhere in the body. This difference between two sharply demarcated tumours must reflect particularly adhesive and infiltrative properties of HPC cells and not just higher proliferation potential.