1/137. Cytologic features of central neurocytomas of the brain. A report of three cases. BACKGROUND: Although cytologic smears are major tools for intraoperative diagnosis of intracranial tumors, cytologic features of central neurocytoma, a tumor that has been recognized for only about 15 years, have not been described. CASES: Typical central neurocytomas were encountered in three patients: 40 years old/M, 44/M and 31/F. Intraoperative cytologic smears were reviewed, and all tumors were subsequently examined by conventional histology, immunohistology and, in one case, electron microscopy. The important cytologic appearances were sheets of round cells with finely stippled nuclear chromatin and perinuclear haloes. Calcospherites, neuropil islands and rosettelike structures were focally encountered. The background neuropil was finely fibrillated, but the tumor cells possessed no appreciable cellular processes. CONCLUSION: Central neurocytomas possess distinct cytologic features that help with the intraoperative distinction from oligodendrogliomas and other intraventricular tumors. A combined radiologic and morphologic approach to the diagnosis of this tumor is advised. ( info) |
| A case of a neurocytoma involving a nerve root of the cauda equina in a 46-year-old woman is reported. The patient presented with a 2-month history of progressive left lower-extremity weakness and pain and decreased ability to walk, as well as complaints of incomplete voiding. A magnetic resonance image revealed a 7-mm oval mass that was located intrathecally and extended from T-12 to L-1 and was adjacent to a nerve root. No lesions were identified at higher vertebral levels. The mass was excised. On histological examination it was found to have classical features of a neurocytoma. To the best of the authors' knowledge, this is the first report of a neurocytoma occurring in that region. A detailed histological description of this case and review of the pertinent literature are provided. ( info) |
3/137. Extraventricular neurocytoma with ganglionic differentiation associated with complex partial seizures. We report an unusual case of extraventricular ("cerebral") neurocytoma with ganglion cells located in the right temporal lobe in a 9-year-old girl with complex partial seizures and precocious puberty. CT showed a calcified mass with central cystic zones. MR imaging showed a markedly hyperintense predominately solid tumor on both T1- and T2-weighted images, without appreciable contrast enhancement. Cerebral neurocytomas are histologically benign and radical surgery is curative; they should be included in the differential diagnosis of temporal lobe tumors in children. ( info) |
4/137. A distinctive glioneuronal tumor of the adult cerebrum with neuropil-like (including "rosetted") islands: report of 4 cases. Four examples of a novel glioneuronal neoplasm are presented. All tumors affected adults (including two males and two females aged 25-40 years) as supratentorial, cerebral hemispheric masses with associated seizure activity and, in one case, symptoms of raised intracranial pressure and progressive hemiparesis. CT scans in two cases revealed hypodense masses without calcification. MRI scans at presentation demonstrated, in all cases, solid T1-hypointense and T2-hyperintense tumors with mass effect in one instance but no edema or contrast enhancement. Only one was relatively circumscribed on neuroradiologic study. All were infiltrative in their histologic growth pattern and predominantly glial in appearance, being composed mainly of fibrillary, gemistocytic, or protoplasmic astroglial elements of WHO grade II to III. Their distinguishing feature was their content of sharply delimited, neuropil-like islands of intense synaptophysin reactivity inhabited and rimmed in rosetted fashion by cells demonstrating strong nuclear immunolabeling for the neuronal antigens NeuN and Hu. These cells included small, oligodendrocyte-like ("neurocytic") elements as well as larger, more pleomorphic forms. Two cases contained, in addition, well-differentiated neurons of medium to ganglion-cell size. Proliferative activity was observed principally within the glial compartment; two cases contained mitotic figures and exhibited relatively elevated MIB-1 indices (6.8% and 8.2%). One of the latter progressed and proved fatal at 30 months following subtotal resection and radiotherapy. The three other patients are alive at intervals of 14 to 83 months, two tumor-free and one with extensive disease associated with the appearance of enhancement on MRI. This glioneuronal tumor variant may pursue an unfavorable clinical course. ( info) |
5/137. Central neurocytoma with malignant course. Neuronal and glial differentiation and craniospinal dissemination. Central neurocytoma is a benign neuronal tumor of young adults in the lateral cerebral ventricles with characteristic X ray and light microscopic findings. In many respects typical central neurocytoma is reported below, with recurrence in the third month requiring reoperation. death ensued in the fifth postoperative month. Subsequent histology proved progressive vascular proliferation and increasing, unusual glial differentiation of the neuronal tumor. At autopsy tumorous seeding blocked the liquor circulation. A thin tumorous layer covered the surface of all ventricles, the cerebellum and medulla oblongata. The GFAP positive cells out-numbered the synaptophysin positive ones. Increase of GFAP positivity and vascular proliferation of the central neurocytoma may be alarming signs suggesting a malignant course in addition to the other atypical features. ( info) |
6/137. Sudden death due to a central neurocytoma. The central neurocytoma is a common, usually intraventricular tumor with bland histologic features. We report a case of a 51-year-old man who died suddenly. At autopsy, a neurocytoma with acute hemorrhage filled the anterior left lateral ventricle. The tumor matrix and surrounding brain tissue contained accumulations of hemosiderin. Previously, 2 cases of central neurocytoma with associated hemorrhage have been reported. hemorrhage appears to be a serious complication associated with these neoplasms. ( info) |
| The authors report on a 17-year-old boy who suffered from slowly progressive and long-standing symptoms of ataxia, neck pain, and headache. Computerized tomography (CT) and magnetic resonance (MR) imaging revealed a tumor arising from the floor of the fourth ventricle that resulted in a moderate hydrocephalus. A partial resection was performed. Histological and immunohistological findings led to the diagnosis of an atypical central neurocytoma of the fourth ventricle. The imaging features on CT scanning, MR imaging, and proton MR spectroscopy studies, the clinical picture, and the prognosis of this very unusual tumor are discussed. Three cases of neurocytomas in the posterior fossa have been described to date; however, in all three cases some atypical aspects were present. In the present case, with the exception of the very unusual location, both imaging findings and clinical history perfectly met the definition of this rare tumor. ( info) |
8/137. Atypical central neurocytoma: report of a case. Central neurocytomas are rare, relatively benign intraventricular neoplasms composed of uniform round cells with neuronal differentiation. The majority of previously reported central neurocytomas did not recurr after tumor removal and the patients had favorable postoperative outcomes. Only a few cases with malignant histopathology or malignant behavior have been noted. Atypical central neurocytoma is a new entity that was first described in the literature in 1997. The tumors have been noted to exhibit a Ki-67 labeling index of 2% or more, or vascular proliferation, mitoses, and necrosis, or both. Atypical histologic findings are usually associated with a somewhat less favorable clinical course and requires postoperative radiotherapy. We report a unique case of a 33-year-old man with a large intraventricular central neurocytoma. The characteristic histopathologic picture, the immunoreactivity for both synaptophysin and neuron-specific enolase, and the ultrastructural features of neuronal differentiation distinguished it from ependymoma and oligodendroglioma. The mitotic activity (up to 3 mitoses/10 high power field) and the high percentage of Ki-67-staining tumor cells (labeling index, 5.0%) in our case were consistent with the atypical variant of central neurocytoma. The patient underwent craniotomy and partial resection of the tumor. Unfortunately, he died of hydrocephalus and brain edema, the next day. ( info) |
9/137. Intraventricular neurocytoma with prominent myelin figures. A case is reported of intraventricular neurocytoma that had characteristic light microscopic findings of neurocytoma with prominent intracytoplasmic concentric lamellar structures mimicking myelin sheaths. On routine H&E-stained sections, this tumor showed intracytoplasmic vesicular bleb-like structures having eosinophilic cores that were consistent with ultrastructural concentric lamellar structures. Immunohistochemically, this tumor was immunoreactive for synaptophysin and neurofilament, but negative for antibody to glial fibriallary acidic protein. Electron microscopic findings fulfilled the criteria for neurocytoma, with the presence of neurosecretory granules and neurotubules. These findings may suggest dual differentiation of this tumor into neurocytes and oligodendrocytes. ( info) |
10/137. Chemotherapy in patients with recurrent and progressive central neurocytoma. BACKGROUND: Recurrent central neurocytoma is very rare and to the authors' knowledge data regarding its response to chemotherapy currently are not available. methods: Three patients with progressive neurocytoma received chemotherapy after their informed consent was obtained. disease recurred in two patients after surgery and radiotherapy and in one patient after surgery. The treatment regimen was comprised of etoposide, 40 mg/m(2)/day, for 4 days; cisplatin, 25 mg/m(2)/day, for 4 days; and cyclophosphamide, 1,000 mg/m(2), on Day 4; this cycle was repeated every 4 weeks. RESULTS: Stabilization of disease was observed in 2 patients and complete remission was observed in 1 patient; at last follow-up, these responses had been maintained for 15 months, 18 months, and 36 months, respectively. CONCLUSIONS: In this small series, this therapeutic regimen led to long term disease reduction, and merits further study. ( info) |