Cerebral amyloid angiopathy (CAA) with presentation as a brain inflammatory pseudo-tumour.

Cerebral amyloid angiopathy (CAA) is frequent but often asymptomatic. It can induce lobar haemorrhage, rapidly progressive dementia or recurrent transient neurological symptoms, other presentations being less frequent. We report 3 patients in their sixties presenting with a space occupying lesion which was the first manifestation of CAA. They were operated with a diagnosis of cerebral tumour. In all three cases, macroscopy was similar, the lesions were superficial in the cerebral cortex and the preoperative diagnoses were glioblastoma, meningioma and cavernoma. Histologically, the lesions consisted of a large inflammatory granuloma with numerous lipophages and siderophages surrounding capillaries with prominent endothelial cells. Vessels in the near cortex and meninges and within the granuloma harboured heavy amyloid deposits immunolabelled by anti-P component, anti-protein beta A4 with a A40 predominance and anti-apolipoprotein E. Adjacent cerebral cortex showed reactive gliosis and rare senile plaques. Amyloidosis is rarely considered among diagnoses of space occupying lesions. In our three cases, CT scan and MRI changes were related to the presence of an inflammatory granuloma around foci of haemorrhage and amyloid laden vessels.

Focal cortical dysplasia with glioproliferative changes causing seizures: report of 3 cases.

In contrast to neoplasia, lesions of focal cerebral dysplasia are thought to be completed developmental processes of abnormal neuronal migration. We present three children with seizures resulting from brain lesions which pathologically demonstrate regions of both clearcut focal cortical dysplasia and also hypercellularity and monomorphism typical of proliferative lesions such as low grade glial tumor. These cases suggest the existence of a distinct subgroup of patients with prominent glioproliferative changes in association with focal cortical dysplasia, challenging the conventional dichotomy between dysplastic and proliferative categories of brain lesions. Recognition of patients with dual pathology may be of practical as well as theoretical importance.

Chemokine receptors in HIV-1 infection of the central nervous system.

Several members of the chemokine receptor are used as coreceptors for HIV-1 infection in the central nervous system (CNS). CCR5 and CCR3 are coreceptors together with CD4 for HIV-1 infection of microglia, the major target for HIV-1 infection in the CNS. Microglia express CXCR4, but their infection by HIV-1 viruses that use only CXCR4 as a coreceptor is relatively inefficient. CXCR4 is also expressed in subpopulations of neurons that are resistant to HIV-1 infection. Additional orphan chemokine receptors that can mediate HIV-1 or SIV entry are expressed in the brain or neurally-derived cell lines, but their role in CNS infection has not been defined. The pattern of chemokine receptor expression in the brain is likely to determine the tropism of HIV-1 for particular CNS target cells and to impact inflammatory and degenerative mechanisms associated with CNS infection.

Localization of HIV-1 co-receptors CCR5 and CXCR4 in the brain of children with AIDS.

The chemokine receptors CCR5 and CXCR4 are co-receptors together with CD4 for human immunodeficiency virus (HIV)-1 entry into target cells. Macrophage-tropic HIV-1 viruses use CCR5 as a co-receptor, whereas T-cell-line tropic viruses use CXCR4. HIV-1 infects the brain and causes a progressive encephalopathy in 20 to 30% of infected children and adults. Most of the HIV-1-infected cells in the brain are macrophages and microglia. We examined expression of CCR5 and CXCR4 in brain tissue from 20 pediatric acquired immune deficiency syndrome (AIDS) patients in relation to neuropathological consequences of HIV-1 infection. The overall frequency of CCR5-positive perivascular mononuclear cells and macrophages was increased in the brains of children with severe HIV-1 encephalitis (HIVE) compared with children with mild HIVE or non-AIDS controls, whereas the frequency of CXCR4-positive perivascular cells did not correlate with disease severity. CCR5- and CXCR4-positive macrophages and microglia were detected in inflammatory lesions in the brain of children with severe HIVE. In addition, CXCR4 was detected in a subpopulation of neurons in autopsy brain tissue and primary human brain cultures. Similar findings were demonstrated in the brain of adult AIDS patients and controls. These findings suggest that CCR5-positive mononuclear cells, macrophages, and microglia contribute to disease progression in the central nervous system of children and adults with AIDS by serving as targets for virus replication.

[Amyloidosis: definition and classification]. / L'amylose, les amyloses: définition et classification.

Amyloidoses are diseases characterized by deposits of altered proteins in the tissues. The amyloid deposit is always extracellular and presents a fibrillary conformation. 85% of the amyloid protein is constituted of a specific protein of each variety of amyloidosis, while the other 15% consists of other proteins and glycoproteins common to all types of amyloidosis. The same amyloid protein can be associated with various clinical forms and, inversely, different proteins can give the same clinical expression. It is therefore preferable to adopt a biochemical classification of amyloidosis. This classification is based on the identification of the various amyloid proteins by immunohistochemical analysis. About fifteen different amyloid proteins have already been identified. Hereditary amyloidoses are the most heterogeneous forms and amyloidoses of the nervous system are still under investigation. Immunohistochemical analysis of the majority of amyloidoses (represented by amyloidosis AA and AL) can now be performed routinely on tissue samples.

[Embryonal carcinoma and anaplastic seminoma of the testis: diagnostic difficulties]. / Carcinome embryonnaire et séminome anaplasique du testicule: difficultés diagnostiques.

In this case report concerning a testicular tumor, the difficulty of discriminating between embryonic carcinoma with granulomatous reaction and anaplastic seminoma is described. According to the literature and the findings of the present case, the value of immunohistochemical investigations is emphasized, especially the use of anti cytokeratin antibody in the diagnosis of embryonic carcinoma. Therapeutic issues stress the importance of such a diagnosis. Furthermore the immunohistochemical identification of embryonic carcinoma in every case should lead to a new classification of the so-called anaplastic seminoma's entity.

Non-Hodgkin malignant lymphomas and peripheral neuropathies--13 cases.

Non-Hodgkin's malignant lymphomas (NHML) are malignant lymphoid proliferations which may be of B or T cell type. Thirteen observations of an association between peripheral neuropathy and B type NHML are reported. None of the cases had evidence of meningeal propagation or neurotoxicity from chemotherapy. The NHML were classified according to the Working Formulation and Kiel classifications. The various mechanisms of peripheral neuropathy in these cases were split into four broad groups. Group I consisted of four cases in which the peripheral nerve lesions were directly linked to a propagation of malignant cells into the peripheral nervous system; this was revealed by autopsy and/or nerve biopsy. Malignant B cell proliferation was demonstrated in three out of four of these cases by immunolabelling of the infiltrates. Group II included three patients whose serum contained a monoclonal immunoglobulin (IgM) with antimyelin activity, and two who had pathological IgM deposits in endoneurial connective tissue. Group III comprised two cases. The immune dysfunction of the NHML was responsible for a Guillain-Barré syndrome in one, and for a chronic inflammatory demyelinating polyneuropathy in the other. Group IV included two patients in whom the mechanism of the peripheral neuropathy, although almost certainly directly related to the NHML, could not be determined beyond doubt. The peripheral neuropathy might have been a result of a paraneoplasic process or, possibly, an undetected lymphomatous invasion of nervous tissue. All these cases of clinically diverse peripheral neuropathy, which either occurred before the discovery of the haemopathy or arose as complications of it, are discussed along with similar observations reported in the literature. Immunolabelling of lymphomatous proliferations and nerves is now of considerable value for classifying and indicating the exact aetiology of the peripheral neuropathy. It can also detect pathogenic consequences of any associated monoclonal dysglobulinemia. In any event, a direct link between the peripheral neuropathy and NHML represents an indication for intensification of specific chemotherapy, which in some of our patients led to significant regression of the peripheral neuropathy. Nonetheless, in some cases, the link between peripheral neuropathy and NHML could not be established with certainty. Long-term follow-up is essential in such cases. The present results show the importance of a case by case study of patients with NHML and peripheral neuropathy.