[Meningeal hemangiopericytomas. A retrospective reciew of 20 cases]

Meningeal hemangiopericytomas (MHP) account for 2% of meningeal tumours. Clinical features, radiology findings, therapy and outcome of 20 MHP operated in our department from 1965 through 1995 were analyzed to determine presurgical features for diagnosis, histologic diagnostic criteria and the role of adjuvant post-operative radiotherapy.

In conformity with the new WHO classification which differentiates MHP from meningiomas, 20 patients with tumors compatible with this definition were reviewed.

The clinical features differed slightly from meningiomas. Only epidemiologic data were different. The CT and MRI scanning gave no preoperative distinction between MHP and meningiomas. Angiography played a predominant role in this distinction. The 20 patients were operated. Twelve received post-operative radiotherapy. The rate of local recurrency was 45%. Of these, 88% did not receive radiotherapy post-operatively. Two patients (10%) presented late recurrence and three patients (15%) one or more extra-neural metastases. Two patients received radiosurgical treatment. In one case with disseminated metastasis, chemotherapy was used without success. Three patients died during the follow up.

Considering our review and the current literature, it seems that complete excision followed by adjuvant radiotherapy of more than 50 Gy significatively reduces the risk of recurrence (p < 0.0001). Radiosurgery is indicated for recurrent tumors measuring less than 30 mm in their greatest diameter.