Intracranial mesenchymal chondrosarcoma with osteoid formation: report of a pediatric case.

CASE REPORT: We present a case of a 14-year-old girl with a 3-week history of severe progressive headache and intermittent vomiting. Magnetic resonance imaging (MRI) revealed a large intensely enhancing mass, which seemed to arise from the right side of the cerebral fossa with implant base in the inferior face of the tentorium and significant mass effect on the nearby structures. A presumptive preoperative diagnosis of meningioma was made. Subtotal surgical resection was performed using the occipital approach. Histologically the neoplasms had the classic features of a mesenchymal chondrosarcoma associated with the focal presence of osteoid matrix. DISCUSSION: Clinical features, therapeutic approaches and prognosis of this rare tumour are discussed with regard to the known 30 cases in the literature.

Outlet fenestration for isolated fourth ventricle with and without an internal shunt.

Conventional shunting of isolated fourth ventricle is notorious for leading to frequent and severe complications. We present four patients with isolated fourth ventricle who have been treated with open posterior fossa surgery together with either outlet fenestration alone or outlet fenestration and a fourth ventricle-spinal subarachnoid space (SSS) shunt. A survey of the relevant literature did not yield any other case reports of fourth ventricle shunting to the SSS under such circumstances. This paper discusses the reasons for choosing this mode of treatment. The main advantage of this technique is that the catheter is inserted along the anatomical long axis of the fourth ventricle. This positioning lessens the possibility of irritating or penetrating the brain stem. Moreover, as a more physiological solution, the shunt does not require a valve system. Because of these advantages, internal fourth ventricle-SSS shunting is proposed as a valid alternative to the "classic" fourth ventriculo-peritoneal shunt.

Mutism after surgical removal of a cerebellar tumor: two case reports.

The authors report two pediatric cases of transient mutism that occurred after surgical removal of a medulloblastoma and a pilocytic astrocytoma of the vermis and discuss the pathophysiology of this syndrome. Transient mutism has been described for the first time quite recently, even in cases where these tumors were also surgically removed before. Perhaps improvement in imaging and in surgical techniques made neurosurgeons more daring and some interventions that were judged impossible are routinely performed today. If this is the case, postoperative transient cerebellar mutism might be considered the price that must be paid in order to cure more patients with cerebellar tumors.

Infratentorial ependymomas of childhood. Correlation between histological features, immunohistological phenotype, silver nucleolar organizer region staining values and post-operative survival in 16 cases.

We have examined pathological criteria in 16 cases of infratentorial ependymomas of childhood using a conventional histological approach, with immunohistochemistry and silver nucleolar organizer region staining (AgNORs). We have found that some of these criteria are of prognostic value. The following histological features were evaluated in each case: cellular density, cellular or nuclear pleiomorphism, mitosis, focal necrosis, endothelial proliferation and complete loss of differentiation. The expression of the following antigens was also studied: epithelial membrane antigen (EMA), human natural killer (HNK1), glial fibrillary acidic protein (GFAP) and vimentin. Only three histological criteria have been retained as indicative of bad prognosis, i.e., high mitotic index, a large amount of necrosis and complete loss of differentiation. These criteria distinguish ependymomas from anaplastic ependymomas. GFAP was expressed in all tumors while other antigens were more variable. In addition tumors expressing large amounts of GFAP were statistically associated with a better prognosis. Increased vimentin expression associated with a decrease of GFAP immunoreactivity correlated with anaplasia and short survival. EMA was not directly correlated with postoperative survival but may be considered as a further prognostic factor. Finally AgNORs values were not statistically correlated with postoperative survival.

Skull base in trigonocephaly.

The authors present aspects of the skull base in trigonocephalic children. Different patterns on clinical anthropometric investigation, bidimensional computer tomography (CT) scan and three-dimensional (3D) CT scan were studied. We present a series of 27 cases of trigonocephaly operated on in the department of pediatric neurosurgery at the Hôpital des enfants La Timone in Marseille since 1975. The skull base has been studied with CT scan in 12 patients and in 5 a 3D CT reconstruction was performed. A control series of 27 children without synostosis has been studied with the same patterns. We have analyzed in 3D, the volume of the anterior fossa related to the orbital volume, the permeability of basal sutures and the spatial orientation of petrous, sphenoid and zygomatic bones. An analysis of nasoethmoidal complex was performed in relation with hypotelorism. CT scan allows the study of the opening of orbital, nasion-pterional angles and the clinopterional angles, as well as nasion-clinoidal and bipterional distances. A computerized analysis of these data compared with normal skull base permits a new approach to these malformations and the necessity for subdivision of trigonocephaly.

Aqueductal stenosis following mumps virus infection. Case report.

A case of aqueductal stenosis following mumps infection is reported, to the authors' knowledge the 12th case in the literature. The pathogenetic events are discussed and the literature reviewed.

Spontaneous intratumoral hemorrhage after ventriculoperitoneal shunting.

We report a 1 1/2-year-old child with an ependymoma in the posterior cranial fossa. As the computed tomographic scan showed evidence of marked triventricular hydrocephalus, the patient underwent ventriculoperitoneal shunting. Two hours after operation, he developed a fatal intratumoral hemorrhage. The indications and contraindications of ventricular external or internal drainage before posterior cranial fossa tumor removal are briefly discussed.