Liponeurocytoma of the left lateral ventricle--case report and review of the literature.

The reported liponeurocytoma of the left lateral ventricle in a 35-year-old man represents the fifth recorded case of a supratentorial intraventricular liponeurocytoma. In this location, liponeurocytomas are very exceptional, whereas it is the typical site for classic central neurocytomas. Conversely, neurocytomas of the cerebellum are predominantly liponeurocytomas with until now more than 25 reported cases. Thus, cerebellar liponeurocytoma is the most frequent neuroepithelial CNS tumor with adipose-like cells followed by ependymomas with a lipid component and supratentorial intraventricular liponeurocytoma. Adipose-like cells in neurocytomas may originate by lipidization of tumor cells, metaplastic transformation of neuroectodermal cells into fat cells or by true adipocytic differentiation. The present case showed also focal glial differentiation with GFAP-positivity of some tumor cells as often seen in cerebellar liponeurocytomas but much rarer in central neurocytomas. Pathogenetic and nosologic implications of supratentorial intraventricular liponeurocytomas are discussed. Future WHO tumor classification should consider that liponeurocytomas are not restricted to the cerebellum. Reports on cerebellar liponeurocytomas with a less favorable clinical course suggest a WHO grade II for liponeurocytomas.

Lipomas of the internal auditory canal--report of two cases and review of the literature.

OBJECTIVE: Lipomas of the internal auditory canal are extremely rare. So far, only 21 cases have been described in the literature. We present here two of our own cases and review the literature to date with special emphasis on the diagnostic and therapeutic options. METHOD: During the last seven years two lipomas of the internal auditory canal were surgically treated in our department. Despite native and gadolinium-enhanced MRI and a thin-sliced temporal bone CT scan they were misdiagnosed as intracanalicular acoustic neurinomas. RESULTS: Total tumour removal could be achieved, the facial nerve function was conserved, but both patients were rendered functionally deaf after surgery. CONCLUSION: Lipomas' radiological behaviour may mimic acoustic neurinomas; without fat-suppressed T(1)-weighted images they are often preoperatively misdiagnosed as acoustic neurinomas. Although the postoperative morbidity with respect to cochlear and facial nerve function is much higher than in small acoustic schwannomas, early surgery may be justified, because complete removal is only possible in this stage. No reliable data are available concerning the natural history of this kind of lesion.

[Cervical myelopathy induced by calcium pyrophosphate tophus in primary chondrocalcinosis]. / Zervikale Myelopathie durch Kalzium-Pyrophosphat-Tophus bei primärer Chondrokalzinose.

A 78 year old female patient with cervical myelopathy induced by a calcium pyrophosphate dihydrate tophus around the dens axis with clinical signs of a cervical tumor is presented. After operation of the tumor, the diagnosis of a generalized CPPD disease was established retrospectively, where by patient had complained of joint pain already for many years. This known complication of a primary chondrocalcinosis should be a reason for a careful investigation of the cervical spine in CPPD disease, because neurological disturbances might increase the joint destruction in the manner of "Charcot joints".

Cranial neuronavigation with direct integration of (11)C methionine positron emission tomography (PET) data -- results of a pilot study in 32 surgical cases.

BACKGROUND: MRI detects small intracranial lesions, but has difficulties in differentiating between tumour, gliosis and edema. (11)C methionine-PET may help to overcome this problem. For its appropriate intra-operative use, it must be integrated into neuronavigation. We present the results of our pilot study with this method. METHOD: 32 patients with 34 intracranial lesions detected by MRI underwent additional (11)C methionine-PET, because the pathophysiological behaviour or the tumour delineation was unclear. All lesions were treated surgically. In 25 patients PET data could be integrated directly into cranial neuronavigation. FINDINGS: (11)C methionine uptake was observed in 27/34 lesions, 26 of them were tumours: 14 malignant and 7 benign gliomas, 3 gliomas without further histological typing, one Ewing sarcoma and one non-Hodgkin lymphoma. Only one (11)C methionine positive lesion was non-tumourous: it was staged as post-irradiation necrosis in a patient operated on for a malignant glioma. 3/7 (11)C-methionine negative lesions were classified as gliosis (n=2) and M. Whipple (n=1), but 4/7 were tumours: 2 astrocytomas WHO(degrees)II, 1 DNT and one astrocytoma WHO(degrees)III. The sensitivity of (11)C methionine-PET was 87%, the specificity 75%, the positive predictive value 96% and the negative predictive value 43%. In all tumourous cases with positive tracer uptake the borderline area of the tumour was better defined by (11)C methionine-PET than by MRI. INTERPRETATION: A positive (11)C methionine-PET is highly suspicious of a tumour, a negative one does not exclude it. (11)C methionine-PET seems to be more sensitive than MRI for differentiating between tumour and edema or gliosis. Simultaneous integration MRI and (11)C methionine-PET into cranial neuronavigation can facilitate cross total tumour removal in glioma surgery.

Neurofilament H immunoreaction in oligodendrogliomas as demonstrated by a new polyclonal antibody.

We have characterized a new polyclonal antibody against heavy chain (H) of neurofilament which can be used to demonstrate neurofilament H in normal brain tissue and oligodendroglioma cells immunocytochemically and immunochemically. Using this antibody we found neurofilament H-immunoreactive tumor cells in 13 oligodendrogliomas (6 WHO grade II, 7 WHO grade III) out of 84 oligodendrogliomas investigated (59 WHO grade II and 25 WHO grade III). Double immunolabeling and confocal laser scanning microscopy showed colocalization of neurofilament H and glial fibrillary acidic protein in certain oligodendroglioma cells. Colocalization of neurofilament and synaptophysin was observed only rarely. The results support the notion that oligodendrogliomas consists of a heterogeneous cell population displaying various stages of differentiation and dedifferentiation. The occurrence of neurofilament H-immunoreactive tumor cells in oligodendrogliomas is not related to the survival of the patients.

[Metaplastic meningioma with cartilaginous differentiation]. / Metaplastisches Meningeom mit kartilaginärer Differenzierung.

A meningioma with cartilaginous areas is described. The tumour arose in the region of the right sphenoid wing in a 74-year-old woman. Histologically, it showed large areas of a typical meningothelial meningioma, among which numerous cartilaginous islands and some chondroid regions, obviously of intermediate (meningothelial/cartilaginous) differentiation, could be seen. Cartilaginous tumour areas showed lower MIB1-labelling indices than typical meningioma regions, where an increased proliferative activity was seen focally. The current WHO classification lists such tumours as metaplastic meningiomas, reflecting the potential of meningioma cells for mesenchymal differentiation. Metaplastic meningiomas may show different metaplasias (xanthomatous, osseous, lipomatous, cartilaginous, etc.). Extensive cartilaginous metaplasias are very uncommon. Identification of typical meningioma areas is the key for the diagnosis of this meningioma variant.

[Axillary nerve paralysis after playing squash. A case report]. / Axillarisparese nach Squash-Spielen. Ein Fallbericht.

A 27-year-old otherwise healthy male presented with an isolated but complete axillary nerve palsy after excessive squash playing. When repeated electromyographic investigations showed no signs of reinnervation in the deltoid muscle, surgery was performed in order to restore nerve function. Intraoperatively, the nerve showed a short segment of thinning about 2 cm distally the nerve's origin from the posterior fascicle. As intraoperative electrophysiological testing was also negative (no electrically evoked nerve action potentials across the lesion) the suspicious nerve segment was resected and nerve continuity restored by sural grafts. Histologically, no intact nerve structures could be found at the site of the thinning. Most likely the lesion was caused by traction forces. Follow-up studies showed reinnervation of deltoid function over time.

[Meningeal melanocytoma]. / Das meningeale Melanozytom.

A 38-year-old man presented with an intracranial extra-axial tumour at the base of the left posterior fossa which proved to be a meningeal melanocytoma. Meningeal melanocytoma is a rare, benign melanotic tumour of the leptomeninges occurring predominantly in the posterior fossa or the upper spinal cord in adults. It shows characteristic cytologic features with isomorphic epitheliod or spindle-shaped cells, often with prominent nucleoli and a variable content of intracytoplasmic melanin. It usually lacks signs of malignancy such as high mitotic rate, necroses or infiltrative growth and shows a low labeling index in proliferation marker studies. Its immunohistological profile with S-100 protein-, vimentin- and HMB-45-positive tumour cells is similar to that of (primary or metastatic) malignant melanoma. This differential diagnosis is crucial because of the totally different therapeutic and prognostic implications. Therefore, everyone dealing with surgical neuropathology should be familiar with the rare, but clinically important diagnosis of meningeal melanocytoma.

Prognostic implication of histopathological, immunohistochemical and clinical features of oligodendrogliomas: a study of 89 cases.

Histopathological, immunohistochemical and clinical parameters were correlated with survival in 89 cases of oligodendroglioma (65 patients with grade II and 24 patients with grade III of the WHO classification). Median survival time and 5-year survival rate were 3.5 years and 76% for patients with oligodendroglioma grade II and 0.875 years and 23% for patients with oligodendroglioma grade III. The tumor biopsy specimens were immunohistochemically analyzed for Ki 67 (MIB-1), vimentin, glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE) and synaptophysin. MIB-1 nuclear labeling index ranged from 0.0% to 33.4%; vimentin-immunoreactive tumor cells were found in 25 cases. MIB-1 nuclear labeling index and vimentin immunoreaction showed a significant statistical correlation to the 5-year survival rate of the patients. Tumors with vimentin expression (n=25) and/or high MIB-1 labeling index (n=26) had a poorer prognosis than tumors lacking vimentin expression (n=57) and/or displaying a low MIB-1 labeling index (n=56). The expression of immunoreactivity for GFAP (n=53), NSE (n=23) and synaptophysin (n=15) appeared to be of no prognostic relevance. Patients with gross total tumor resection (n=47) had a median survival time and 5-year survival rate of 3.3 years and 84% compared to 1.2 years and 42% for patients with subtotal resection (n=41). The comparison between patients who underwent surgery alone (n=53) and those who had surgery plus postoperative radiation therapy showed no significant survival benefit from postoperative radiation therapy. In conclusion, tumor grade, MIB-1 labeling index, expression of vimentin and the extent of surgery are shown to be of prognostic relevance for patients with oligodendroglioma.

Multidrug resistance in glioblastoma. Chemosensitivity testing and immunohistochemical demonstration of P-glycoprotein.

Chemosensitivity of previously untreated glioblastomas to mitoxantrone, methotrexate, ACNU and BCNU was tested on cultured tissue. Sixteen of 62 tumors were partially chemosensitive in vitro. The monoclonal antibody C 219 was used to demonstrate the presence of p-glycoprotein in the 16 sensitive and five highly resistant glioblastomas. All 21 tumors identically expressed p-glycoprotein. These results show that untreated glioblastomas primarily express p-glycoprotein even if they are at least partially chemosensitive in vitro. Therefore, immunohistochemical demonstration of p-glycoprotein with the monoclonal antibody C 219 can not provide reliable information on short term resistance of the individual tumors to antineoplastic drugs. P-glycoprotein expression could, however, help to explain the disappointing overall long-term efficacy of chemotherapy by showing the existence of cell populations with early drug resistance in these tumors.

Follow-up in carriers of the 'MELAS' mutation without strokes.

Eight carriers of the A3243G mutation of mitochondrial DNA without stroke-like episodes were monitored for up to 7 years in clinical and metabolic studies, by magnetic resonance imaging (MRI) and positron emission tomography (PET). None developed mitochondrial encephalopathy (MELAS), but 2 developed diabetes mellitus, 1 terminal kidney failure and 2 cardiomyopathy. One patient improved markedly under ubiquinone. Electroencephalography showed progressive slowing in 2 cases, but electrophysiological tests and MRI were otherwise noncontributary. PET showed widespread cortical and basal ganglion metabolic deficits in 6 cases. We conclude that internal medical complications are more common than MELAS in adult carriers of the mutation. PET findings, firstly reported in such patients, suggest that chronic subclinical encephalopathy is very frequent, and PET may play a role in monitoring in the future.

Mitoxantrone-induced DNA strand breaks in cell-cultures of malignant human astrocytoma and glioblastoma tumors.

In this study mitoxantrone (Mtx) induced DNA strand breaks were measured with the alkaline elution technique in short term cell cultures derived from human gliomas. Glioblastomas or astrocytomas from 5 patients who underwent intracranial surgery were cultured and incubated i h with different concentrations of Mtx (0, 0.01, 0.1 and 1.0 microgram/ml). The alkaline elution method was modified to measure DNA lesions in human gliomas. Mtx induced DNA strand breaks in a dose dependent manner in all cell cultures tested. There was a linear increase of DNA strand break frequency induced by Mtx between 0.01-1.0 microgram/ml. concerning these in vitro data, Mtx might be potentially useful for the treatment of patients with malignant brain tumors.

Pleomorphic xanthoastrocytoma: report of six cases with special consideration of diagnostic and therapeutic pitfalls.

BACKGROUND: Pleomorphic xanthoastrocytoma (PXA) is a rare clinicopathologic entity that occurs typically in young patients. Improved neuroradiologic techniques, especially gadolinium-enhanced magnetic resonance imaging (MRI), reveal a characteristic tumor appearance. METHODS: We present six cases of PXA operated on with unusual clinical course, elucidating different clinical implications. RESULTS: Two patients showed subsequent progression into a malignant glioma, one case was a primary anaplastic PXA. The latter case had not previously been reported in the literature. Increased mitotic activity seems to indicate a worse clinical course; whereas focal infiltration of the brain does not necessarily lead to malignant transformation. CONCLUSIONS: Surgical removal is the treatment of choice. A consequent follow-up is mandatory in order to detect a potentially malignant recurrence as early as possible and to select patients who need additional therapy.

[Metaplastic ossification in an acoustic neurinoma]. / Metaplastische Ossifikation in einem Akustikusneurinom.

We report the case of a 52-year-old woman with a cerebellopontine angle tumor, which appeared to have arisen from the 8th nerve. Microscopically the tumor was proved to be an acoustic neurinoma and showed unusual findings such as inclusions of mature bone and bone marrow. The histogenesis and diagnostic relevance of the very rare heterotopic osteogenesis in acoustic neurinomas is discussed.