Clinical features and management of intracranial subependymomas in children.

Subependymoma is a rare low-grade glioma of the central nervous system that occurs most commonly in middle-aged and elderly men and rarely in children. Only a few paediatric patients with subependymomas have been reported. The authors retrospectively analysed five paediatric patients (4 males and 1 female; mean age 8.6 years; age range 5-13 years) at a single institute from July 1998 to April 2009 and summarised the clinical characteristics and management of paediatric intracranial subependymoma. The most common symptom in these five paediatric patients with subependymoma was intracranial hypertension. The tumours were located in the fourth ventricle in two patients, in the fourth ventricle with extension to the cerebellopontine angle (CPA) in one patient; in the right CPA exclusively in one patient, and intraparenchymally in the left parietal lobe in one patient, the latter two of which are rare locations for subependymoma. Surgery was performed on all five patients. The surgical approach was selected as appropriate for the tumor location. Total resection was achieved in three patients, and subtotal resection in two. All five patients had good outcomes without recurrence. We conclude that surgery is the optimal therapy for paediatric patients with intracranial subependymoma.

Nonenhancing tumors of the spinal cord.

OBJECT: Enhancement of pathological entities in the central nervous system is a common finding when the blood-brain barrier has been compromised. In the brain, the presence or absence of gadolinium enhancement is often an indicator of tumor invasiveness and/or grade. In the spinal cord, however, contrast enhancement has been shown in all tumor types, regardless of grade. In this study the authors explore the incidence of nonenhancing tumors of the spinal cord and the clinical course of patients with these lesions. METHODS: A retrospective analysis was conducted in which investigators examined the patterns of enhancement of histologically proven intramedullary spinal cord tumors that had been evaluated at the Mayo Clinic between 1998 and 2002. The tumors that did not enhance were the subject of this report. RESULTS: A total of 130 patients with intramedullary tumors were evaluated. Of those, 11 patients (9%) had tumors that did not enhance. Histologically, a majority of tumors were astrocytomas (eight low-grade and two high-grade lesions); one tumor was a subependymoma. Morphologically, most of the tumors were diffuse and none had associated cysts. Tumors spanned from two to seven levels and were located throughout the spinal cord (four cervical, three cervicothoracic, one thoracic, and three thoracolumbar). Biopsy procedures were performed in eight patients, subtotal resection was performed in two, and gross-total resection in one. After a mean follow-up period of 19 months, tumors remained stable in eight patients but progressed in three, two of whom died. CONCLUSIONS: A number of intramedullary spinal cord tumors will not enhance after addition of contrast agents. The absence of enhancement does not imply the absence of tumor.

Supratentorial extraventricular ependymal neoplasms: a clinicopathologic study of 32 patients.

BACKGROUND: Published research on the clinicopathologic features of extraventricular ependymal neoplasms of the cerebral hemispheres has been scant. METHODS: Thirty-two archival cases were studied to investigate the prognostic impact of clinicopathologic parameters including flow cytometry, the proliferation (Ki-67) labeling index, and p53 expression. RESULTS: Among these 32 cases were 2 subependymomas, 19 ependymomas, and 11 anaplastic ependymomas. No significant gender predilection was observed, and 45% of patients were in their second or third decade of life. The left cerebral hemisphere was 1.5 times more commonly involved. On available imaging studies, lesions were often cystic, with or without a mural nodule. Tumors expressed glial fibrillary acidic protein (87%), S-100 protein (77%), cytokeratin (43%), and epithelial membrane antigen (17%). Ki-67 proliferation index paralleled tumor grade. Immunoreactivity for p53 protein was observed in the 2 cases of subependymoma, in 10 of 11 anaplastic ependymomas, and in 6 of 17 ependymomas. Flow cytometry performed in 27 tumors revealed diploidy in 20 cases and aneuploidy in 4 cases (3 anaplastic and 1 classic ependymomas), with S-phase fraction ranging from 0.2-9.7. Eleven subjects were additionally treated with radiotherapy, and 3 with chemotherapy. Follow up was available in 25 (78%) patients. CONCLUSIONS: The results of the current study suggest that there is no significant relation between histopathology, Ki-67 proliferation index, p53 immunolabeling, tumor ploidy, and biologic behavior.

Ependymomas.

Ependymomas are uncommon neoplasms of the central nervous system (CNS), and as a consequence, few randomized, clinical trials have been performed, thereby limiting treatment guidelines. A review of the literature would permit the following conclusions regarding treatment. The best management of newly diagnosed ependymoma entails a complete resection corroborated by postoperative contrast-enhanced magnetic resonance imaging (MRI). If an incomplete resection is documented, a second attempt at gross total resection should be considered, given the prognostic significance of complete resection. Small volume residual disease is best managed with involved-field radiotherapy unless postoperative staging (cerebrospinal fluid cytology, neuraxis MRI) documents metastatic disease, which is best managed by craniospinal irradiation. The role of chemotherapy is uncertain and in general would be reserved for patients having previously failed surgery and radiotherapy. Disease-free survival following recurrence is unusual (<15% at 5 years) and suggests intensification of initial adjuvant treatment may best prevent relapse.

Tumours around the foramen of Monro: clinical and neuroimaging features and their differential diagnosis.

The clinical and neuroimaging features of 20 patients with lateral ventricular tumours located around the foramen of Monro were reviewed retrospectively with special emphasis on the differential diagnoses. Histologic types were: eight neurocytomas, four subependymal giant cell astrocytomas (SGCAs), three subependymomas, two fibrillary astrocytomas, and one each of pilocytic astrocytoma, malignant astrocytoma and malignant teratoma. The mean age of the patients with neurocytoma was 29.6 years, with SGCA 13.3 years and with subependymoma 55.3 years. All tumours appeared nodular in shape, and on computed tomography (CT) neurocytomas were either isodense or highdense with the brain, while all subependymomas and SGCAs were lowdense. Calcification was observed in two SGCAs, and one neurocytoma. Five neurocytomas and all four SGCAs showed mild to moderate contrast enhancement, while all three subependymomas showed either no, or scarce, enhancement. Magnetic resonance imaging (MRI) studies were available in 10 patients, with the signal characteristics of four neurocytomas and three SGCAs being nonspecific, while two subependymomas were both hypointense on T1-weighted images and hyperintense on T2-weighted images. Thus important features for differential diagnosis included age of the patient and density on precontrast CT. In this series, either an extensive excision of the tumour or a partial removal, thus relieving the obstruction of the foramina of Monro, usually provided long term survival, with 18 patients surviving a mean of 10.8 years.