18 cases of benign intradural spinal cyst (9 arachnoidal, 2 neuroepithelial, 7 endodermal) are reported and compared with 94 cases (67 arachnoidal, 7 neuroepithelial, 20 endodermal) obtained from the literature. Arachnoidal intradural cysts (AIC) have no sex preference, occur at around the fourth-fifth decades of life and have characteristic intermittent root symptoms. They prefer the thoracic level and the posterior position. (Myelography images the cystic cavity (diverticular form). Surgical removal is usually easy. Neuroepithelial intradural cysts (NIC) are rare, have a 2:1 predilection for females and occur after the fourth decade. They have a serious clinical course similar to intramedullary or extramedullary tumours. They prefer the conus-cauda and the anterolateral positions. They often give rise to manometric block and to albuminocytological dissociation. There may be substantial adhesions to the cord and roots and the intramedullary variety presents no clear plane of cleavage. Endodermal intradural cysts (EIC) have a 2:1 predilection for males and prefer the second and third decades. They may have an intermittent or serious course with signs of root and cord impairment. They prefer the cervical segment (in the anterior position) and the conus-cauda (in the posterior position). As a rule they present manometric block and albuminocytological dissociation. Their frequent tough adhesions to the roots and cord demand special care during their removal.

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.

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.

Cerebral meningiomas are rare tumors in children that represent 1.4% of CNS tumors and 1.5% of intracranial meningiomas. We have analyzed 197 cases of cerebral meningiomas under 16: 178 cases were taken from the available literature and 19 from our series. When comparing pediatric meningiomas with those of adults, we noted some differences. Before the age of 16 there is a slight preference for males; the intraventricular variety is more frequent; cystic meningiomas and the absence of dural attachment are more frequent findings; the neuroradiological diagnosis is more difficult.

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.