Supratentorial dermoid cysts are rare lesions. In eight cases presented here, the lack of recurrence after subtotal removal of the capsule and the good long-term prognosis are emphasized. This finding is in agreement with the literature. The frequent relationship of these lesions with the cavernous sinus suggests a vascular genesis in the development of intracranial dermoid cysts.

A series of 7 cases of PCA aneurysm treated between 1978 and 1992 were analytically reviewed together with 79 cases culled from the literature. In comparison to those localized elsewhere, PCA aneurysms are more frequently large, more frequently present with tumour-like symptoms and appear at an earlier age. Surgical outcome was evaluated in relation to clinical onset, site and size of the aneurysm, the surgical procedures adopted for excluding it and pre-operative clinical grading appeared to influence outcome. The fact that site, size and surgical technique do not significantly influence prognosis is probably due to the rich collateral flow present in the areas fed by the posterior cerebral artery. The authors conclude that, clinically speaking, PCA aneurysms should be considered as a separate group.

The clinical findings and the results of surgical treatment in 16 patients with spinal dermoid or epidermoid tumors are reported. In 9 patients the tumor capsule adhered so tightly to the nervous tissue that part of it was left in situ. In a follow-up study ranging from 5 to 30 years with a mean of 14.2 years only 1 patient had a recurrence of the tumor and 10 patients resumed a normal working life.

We report the long-term outcome of surgery for cerebral hydatid cyst in 12 children. In only one child, who had been operated on for cardiac hydatidosis a year earlier, was the brain cyst known to be secondary. Of the 12 children. 10 had a single cyst and 2 had multiple cysts. Five single cysts were removed intact by “hydatid birth,” two cysts—one single and one multiple—were removed after puncture and aspiration of the cyst fluid, and the other five—four single and one multiple—were accidentally ruptured in the course of the operation. One patient died of infection of the residual space. 2 died of intracranial recurrence of the parasite (7 and 22 months later, respectively), and one. the child with secondary cerebral echinococcosis, died 6 years later of systemic echinococcosis. Eight patients who had a mean follow-up of 28 years are still living and enjoy very good health, both general and neurological. This long-term follow-up with such good results confirms the usually primary character of cerebral hydatid disease, at least in children. The combination of patent ductus arteriosus and ingestion of unboiled animals' milk might well explain how primarv cerebral hvdatid disease develops in children.

Of the 62 patients with intramedullary spinal cord ependymoma treated surgically at our Neurosurgery Division between January 1951 and December 1990 45 had a follow-up of at least 3 years and the longest 30 years. The 28 conus-cauda equina-filum ependymomas operated during the same period are not considered in this study. An analysis of our cases and of the larger published series shows that favourable prognostic factors, apart of course from total tumour removal, which is now usually possible, are a site below the high cervical segments and a mild pre-operative symptom pattern. Patient age at diagnosis, tumour size and "low dose" (< 40 Gy) radiotherapy seem to have no influence on the prognosis. Aggressive surgical removal is the treatment of choice and also for long-term recurrence.