The clinico-surgico-pathological spectrum of myxopapillary ependymomas--report of four unusal cases and review of the literature.

According to the WHO grading system, myxopapillary ependymomas are assigned to WHO Grade I. However, the clinico-pathological spectrum might be very heterogenous. Herein, we report 4 cases exhibiting lumbar tumor masses, 1 causing muscular atrophy over a 30-year period, 3 displaying clinical history of persisting lumbar pain for only several weeks. All tumors were crooked with dura and spinal roots resulting in incomplete resection in three cases. On histological examination, two tumors were almost acellular and showed polycyclic hyaline and fibrotic extracellular matrix leading to differential diagnoses of chordoma, meningioma, fibrolipoma and ependymoma. Finally, together with the immunohistochemical investigations, electron microscopy led to the diagnosis of myxopapillary ependymoma, WHO Grade I, with massive degenerative changes. The other 2 cases presented with the typical neuropathology of myxopapillary ependymomas but showed local recurrence within 1 and 13 years throughout the whole neuraxis, and in 1 case additional metastases of the 3rd ventricle. Although the morphological feature of these myxopapillary ependymomas was benign, the presented cases showed that the biological behavior of myxopapillary tumors might differ greatly and that these tumors present a serious operative and diagnostic challenge. Myxopapillary ependymomas occur most often in the lumbosacral region. Due to the anatomic complexity of the cauda equina, a complete resection can be technically challenging in this region. However, a gross total resection at the primary surgery is the most predictive factor for the outcome.

Histological heterogeneity of human glioblastomas investigated with an unsupervised neural network (SOM).

The histological variability of Glioblastomas (GB) precludes the modern assimilation of theses tumors into a single histological tumor group. As an alternative to statistical histological evaluation, we investigated 1489 human GB in order to discover whether they could be correctly classified using Self-Organizing Maps (SOM). In all tumors 50 histological features, as well as the age and sex of the patients, were examined. Four clusters of GB with a significance of 52 (maximal significance 60) were found. Cluster C1 contained 37.47% of all GB and 41.09% of all polymorphic glioblastomas (PG). Cluster C2 included 35.06% of all GB and 44.96% of all giant cell glioblastomas (GCG). Cluster C3 contained 16.45% of all GB with a significant component of astroblasts, glioblasts and oligodendroglia. Cluster C4 included 11.01% of all GB, 87.80% of the gliosarcomas (GS) and 36.72% of all GCG. Placing a series of component windows with their maps side by side allows the immediate recognition of the dependencies on variables and the determination of variables necessary to build the specific clusters. The SOM allow a realistic histological classification, comparable to the actual classification by the WHO. In addition, we found new, small subclusters of human GB which may have a clinical significance. With SOM one can learn to discriminate, discard and delete data, select histological and clinical or genetic variables that are meaningful, and consequently influence the result of patient management.

Hypothalamic modulation of growth hormone secretion in the rhesus monkey: evidence from intracerebroventricular infusions of glucose, free fatty acid, and ketone bodies.

To evaluate the hypothalamus as a possible site of metabolic modulation of GH secretion, we studied the GH response to insulin hypoglycemia (IHG) and nicotinic acid (NA)-induced FFA depression in the absence and presence of third ventricular (ivt) infusions of glucose, oleic acid (Ol-Ac), or beta-hydroxybutyrate (beta OHB). Four rhesus monkeys had been prepared for chronic remote iv and ivt infusions as well as blood sampling from the adjacent room. Statistical evaluation used a two-way analysis of variance and individual comparisons with Tukey's Studentized range test. The GH response (area under the curve +/- SE) to IHG was significantly reduced by a concomitant ivt glucose infusion (control, 1.0 +/- 0.1; IHG, 12.1 +/- 3.3; IHG plus ivt glucose, 7.0 +/- 1.2 microgram/L.120 min). The GH response to FFA depression was significantly reduced by ivt Ol-Ac or beta OHB infusion (control, 6.0 +/- 1.0; NA, 51.5 +/- 4.1; Na plus Ol-Ac, 81.2 +/- 1.3; NA plus beta OHB, 38.6 +/- 3.5 microgram/L.300 min). Introcerebroventricular infusions of glucose, Ol-Ac, or beta OHB alone had no effect on plasma GH, glucose, FFA, or beta OHB concentrations. These results provide evidence for a hypothalamic site of metabolic modulation of GH secretion in the rhesus monkey. This does not exclude an additional effect directly at the pituitary gland.

The neuropathology and epidemiology of AIDS. A Berlin experience. A review of 200 cases.

The brains of 200 patients who died with Acquired Immunodeficiency Syndrome (AIDS) from Berlin were examined retrospectively. This study was specifically intended to evaluate and document the prevalence of neuropathologic abnormalities, establishing the frequency of the various types of structural lesions, their combinations, their relative incidence, and the risk factors involved in different age groups. The data were compared and contrasted with the findings reported from other parts of the world and other German cities. It was found that the mean age of this group of patients was 41.4 years old, 75% were homosexual/bisexuals (H/B) and 18.5% were drug abusers (DA). Only 5.5% were women. Brain parenchymal changes, called in this report, HIV-related encephalopathy (HIVRE), characterized by vacuolization or spongy changes and astrocytosis in the subcortical white matter, and occasionally in gray matter, were found in 67 patients (33.5%). Drug abusers had a higher incidence of HIVRE (59.5%) compared with homosexual/bisexuals (28%). This is statistically significant (p < 0.0005). CMV encephalitis was found in 26 patients (13%) (8% of the drug abusers in contrast to 13% in the homosexual/bisexuals group). Primary central nervous system lymphoma (PCNSL) was seen in 28 patients (14%) regardless of the risk factor involved. 20 (13%) of the 150 H/B and 3 (8%) of the 37 DA had CMV encephalitis. Of the 150 H/B, 24 (16%) had PCNSL compared with only 4 of 37 (11%) of the DA. A significant incidence of opportunistic infections, both protozoal and viral was found in all groups. Cerebral toxoplasmosis occurred in 68 patients (34%). Microglial (phagocytic) nodules, probably related to CMV or cerebral Toxoplasmosis, were observed in 40 cases (20%). Diffuse microglial proliferation was noted in 104 patients (52%). Cerebral cryptococcosis was found in three patients. Progressive multifocal leukoencephalopathy was seen in 16 patients (8%). Various combinations of CNS pathological processes were found in 44 of the patients (22%). These include concomitant infections with Toxoplasma gondii and HIVRE in 13 patients; Toxoplasmosis and PCNSL in 8 patients; Toxoplasmosis with CMV and HIVRE in 4 patients; Toxoplasmosis with CMV in 2 patients; Toxoplasmosis with PCNSL and CMV in 2 patients; Toxoplasmosis with PCNSL and HIVRE in 2 patients and Toxoplasmosis with PML and HIVRE in 2 patients; Cerebral CMV with PCNSL and HIVRE in 4 patients; Cerebral CMV with HIVRE in 2 patients; PML with PCNSL in one patient; PML with HIVRE in 2 patients; and PML with PCNSL and HIVRE in one patient. Cerebrovascular lesions were found in 34 patients (17%).(ABSTRACT TRUNCATED AT 400 WORDS)

Myelin basic protein (MBP) in human gliomas: a study of twenty-five cases.

Twenty five gliomas (5 oligodendrogliomas, 8 oligoastrocytomas, 5 astrocytomas grades I-II, and 7 malignant astrocytomas-glioblastomas) were studied with the immunohistochemical technique avidin-biotin complex (ABC) for myelin basic protein (MBP). We found four patterns of positivity with variable degrees and frequencies in the different types of tumors. We believe this method can help in the diagnosis of non-characteristic gliomas, particularly oligoastrocytomas.

Disseminated melanomatosis of the central nervous system and other organs: a case report.

This case represents an example of clinically occult, disseminated neoplastic disease with almost asymptomatic but severe involvement of the central nervous system. The only helpful diagnostic investigation appeared to be cerebrospinal fluid cytology. Extensive post mortem examination was inconclusive as to whether the widespread CNS involvement with melanoma was primary or secondary.

Cerebral lymphoma in AIDS. Clinical, radiological, neuropathological and immunopathological study.

Neuropathological findings from 8 individual cases of cerebral lymphomas in AIDS patients with consideration of the clinical, radiological, immunopathological, and other pertinent data selected from a series of 80 patients between 1985 and 1989 were studied. A wide variation in pathology was noted among our cases. It has been shown that lymphoma as a neuropathological diagnosis can coexist with a wide range of other characteristics, including toxoplasmosis, glial nodules, neuronophagia, degeneration, bleeding, hypoxia, progressive multifocal leucoencephalopathy, and myelopathy, although none of these attributes appeared more than casually interrelated. In general, the late-stage manifestations of lymphoma as were observed in this study, tended to be poorly localized, often simultaneously meningeal, perivascular, and diffuse in character. An important distinction between cerebral lymphomas of AIDS and non-AIDS patients is the highly atypical, clinically unreliable computer tomographic signals observed in several of our cases. Five of the six immunopathological investigations showed a preponderance of B-cell markers, corresponding in toto to high-grade non-Hodgkin lymphoma. One case exhibited immunohistological markers typical of Hodgkin's lymphoma (antibody CD-30). Of 6 obtainable serum specimens from our 8 cases, 4 showed high (greater than 2000) IgG titers against the EBNA-1 antigen of Epstein-Barr virus (EBV), of these three had IgM titers further supporting viral reactivation. One showed a normal IgG titer, yet with a significantly raised IgM titer.

[Histopathologically verified cerebral CT findings in AIDS]. / Histopathologisch verifizierte zerebrale CT-Befunde bei AIDS.

Computer tomographic and histopathological findings in 55 patients who died of the complications of acquired immunodeficiency syndrome, were reviewed retrospectively. In 23 patients (42%) an increased space of the internal or external cerebral spinal fluid was diagnosed. 20 patients (36%) had focal lesions. We differentiated between single, multiple and ring-shaped lesions with contrast enhancement and hypodense lesions. In 12 cases (22%) no CT abnormalities were found. Focal lesions proved to be secondary to toxoplasmosis in 85%. Single lesions were never caused by toxoplasmosis.

The impact of progesterone receptor expression on relapse in the long-term clinical course of 93 benign meningiomas.

BACKGROUND: Previous clinicopathological observations have pointed towards an impact of progesterone receptor (PgR) expression on the clinical course of meningiomas. MATERIALS AND METHODS: EXpression of PgR and the proliferation marker MIB-1 was assessed by immunohistochemistry in the primary tumours of 30 cases of benign, completely resected, recurrent meningiomas and compared with 63 cases of meningioma without recurrence for 14 or more years. RESULTS: Univariate analysis showed a significantly higher risk for recurrence (odds ratio 3.533) for tumours with a low expression of PgR. A tendency for a higher risk for tumours with higher proliferation rate (odds ratio 6.889) was not significant. In 20 cases in which the primary tumour could be compared with its recurrence, no consistent changes of PgR expression were observed. CONCLUSION: Our findings support previous studies that found an association of low or absent expression of PgR with a higher risk of recurrence. This encourages attempts at a hormonal therapy for patients with PgR-positive meningioma.

Causal probabilistic modeling for malignancy grading in pathology with explanations of dependency to the related histological features.

This work demonstrates that histological grading of brain tumors and astrocytomas can be accurately predicted and causally explained with the help of causal probabilistic models, also known as Bayesian networks (BN). Although created statistically, this allows individual identification of the grade of malignancy as an internal cause that has enabled the development of the histological features to their observed state. The BN models are built from data representing 794 cases of astrocytomas with their malignant grading and corresponding histological features. The computerized learning process is improved when pre-specified knowledge (from the pathologist) about simple dependency relations to the histological features is taken into account. We use the BN models for both grading and causal analysis. In addition, the BN models provide a causal explanation of dependency between the histological features and the grading. This can offer the biggest potential for choice of an efficient treatment, since it concentrates on the malignancy grade as the cause of pathological observations. The causal analysis shows that all ten histological features are important for the grading. The histological features are causally ordered, implying that features of first order are of higher priority, e.g. for the choice of treatment in order not to allow the malignancy to progress to a higher degree. Due to the explanations of feature relations, the causal analysis can be considered as a powerful complement to any malignancy classification tool and allows reproducible comparison of malignancy grading.

[Ultrastructural systematization of vascular changes in gliomas]. / Ultrastrukturelle Systematik der Gefässveränderungen bei Gliomen.

The fine structural features of microcirculation in benign gliomas, as compared to those in glioblastomas have insufficiently been studied. 36 astrocytomas and oligoastrocytomas (grades I and II) were examined with the electron microscope in order to classify the arterioles, capillaries and venules of these tumours. In all the gliomas, the number of arterioles was smaller than in the normal brain parenchyma. A thickening of the subendothelial basement membrane could be assessed regularly. In the architecture of the small vessels numerous transitional forms could be found in many cases. On this basis the designation "capillary-like" and "venule-like" vessels seems to be justified. As a rule, the venule-like vessels are more numerous than the capillaries. The pericapillary and particularly the perivenular spaces are frequently dilated. In a few areas no continuous perivascular sheath of astrocytic foot processes are formed. At places glial processes can be found in the perivascular spaces which are not covered by a basement membrane. Lack of arterioles can lead to disturbances in autoregulation, and the frequently pathological structure of the capillaries and venules can result in disordered transport of water and ions with consecutive oedema.

Localization of adrenergic neurons in human and cat meninges.

In human and cat meninges the presence of adrenergic neurons was studied. The human meninges were obtained from 10 adult individuals 1-3 hours postmortem and the 6 cats meninges, one pretreated 7 days before the experiment with 5 mg of 6-OHDopamine intracisternally. In human and cat meninges, adrenergic granulations, located in fibers that form a reticulum around the arterial, arteriolar and small vein vessels were observed. These adrenergic fibers appeared forming a very dense reticulum in the adventitia of the small calibre arteries and in arterioles. In addition, in some vascular sectors, a considerable number of triangular or elongated cells, whose cytoplasm is full of adrenergic granulations can be observed isolated or in close vicinity to the adrenergic reticulum. In the meninges of the cat treated with 6-OH-Dopamine there was no adrenergic granulation. Furthermore, the radioenzymatic determination of noradrenaline content in 3 human meninges shows the existence of this amine. The number of cellular elements with adrenergic granulations is notable and permits one to suspect that this cellular system can play an important role in the autoregulation on the cerebral circulation together with the perivascular adrenergic reticulum.

Spinal extradural angiolipoma: case report and literature review.

A case report of a 12-year-old child with a spinal extradural angiolipoma is presented. The tumor was totally removed and a good recovery was obtained. In a review of 43 previous cases, the clinical, radiological, and histological features of the tumor are discussed. It is stressed that spinal angiolipomas and spinal lipomas have to be considered as two different clinicopathological entities in order to ensure adequate treatment and prognosis.

Hemorrhagic infarction of the basal ganglia. An unusual complication of acute leukemia.

Hemorrhagic infarction of the basal ganglia was observed in 2 young adult patients with acute leukemia who presented with progressive hemiparesis combined with severe mental alterations. In case 1 (AML) lethal infarction due to thrombosis of both internal cerebral veins occurred during induction therapy for relapsed leukemia; in case 2 (cALL) a devastating stroke probably due to deep cerebral venous thrombosis happened during the third remission. Neither of them had hyperleukocytosis, signs of infection, disseminated intravascular coagulation or CNS leukemia. We discuss long-term glucocorticoid therapy (case 1) and combined prophylactic CNS treatment (case 2) as possible risk factors for cerebrovascular thrombosis in acute leukemia.

[Intracerebral gliofibroma]. / Intrazerebrales Gliofibrom.

A 14-month-old girl had three epileptiform attacks in the course of 6 months, each consisting of rhythmic movements of the right arm and right hand of 5 minutes' duration, followed by a 15-minute period of weakness. There were otherwise no abnormal neurological signs. Prenatal and perinatal development had been uneventful and the mother was healthy. Computed tomography showed a tumour in the left frontoparietal region. Surgery revealed an intracerebral tumour 7 cm in diameter with two large cysts; it was not sharply demarcated from the brain parenchyma, had no connection with the dura and was not infiltrating the ventricular system. The tumour was completely removed and at follow-up 18 months later there was no evidence of recurrence. Histological and immunohistochemical investigations showed that the tumour consisted of closely interwoven astrocytes and fibroblasts, two different cell types the latter of which does not normally occur in the brain. Exact immunohistochemical analysis of the components of a tumour is important because, unlike pure glial tumours, gliofibromas have a good prognosis after complete resections.

[Malignant meningeal "histiocytosis"]. / Meningeale maligne "Histiozytose".

Two cases of patients with unusual pleomorphic tumors in the meninges are reported. Histologically and immunohistologically, the tumor cells may be histiocytic in appearance. Computed tomography and magnetic resonance imaging scans, however, revealed no lesions in the parenchyma or in the meninges. The cytological examination of the cerebrospinal fluid revealed only a light lymphocytic reaction without tumor cells in both cases and thus led to misinterpretations as meningoencephalitis. One patient presented psychiatric symptoms. Related clinical problems and the possible histogenesis of the tumors are discussed.