Emilie Rouah

Demonstration of Epstein-Barr virus in primary central nervous system lymphomas by the polymerase chain reaction and in situ hybridization☆

Primary lymphomas of the central nervous system (CNS) account for 0.3% to 1.5% of all intracranial neoplasms. Several reports have noted a coincidence between this neoplasm and serologic evidence of Epstein-Barr virus (EBV) infection, but in only a few instances has the EBV genome been demonstrated in these tumors. To further evaluate the frequency of this occurrence, we analyzed primary CNS lymphomas using nucleic acid hybridization methods and the polymerase chain reaction (PCR). In situ hybridization was used in selected cases. Sequences of EBV were found in two of nine cases by PCR and in situ hybridization. Southern blot hybridization of genomic DNA from these samples was negative for EBV. Both tumors arose in patients with conditions shown to produce secondary immunodeficiency, namely, chronic alcohol abuse and diabetes mellitus. We conclude that the association of EBV and CNS lymphoma is not restricted to patients with severe primary immune deficiency, and that PCR can be applied successfully to paraffin-embedded tissue for the detection of low-abundance viral sequences.

Antineuronal Nuclei Immunohistochemical Staining Patterns in Childhood Ependymomas

NeuN, the mouse-derived monoclonal antibody to the reportedly neuron-specific nuclear protein, has been observed to react with many different types of normal, postmitotic neurons throughout the central and peripheral nervous systems. We retrospectively examined 23 surgical specimens (collected from 20 patients) originally diagnosed at our institution between 1983 and 1999 as ependymoma (9), myxopapillary ependymoma (1), anaplastic/malignant ependymoma (10), and primitive neuroectodermal tumor with ependymal differentiation (3). The ependymomas included lesions from the spine (3), cerebrum (5), and posterior fossa (15). Representative formalin-fixed, paraffin-embedded sections from each tumor were subjected to immunohistochemical staining with antibody against NeuN (Chemicon International, Inc, Temecula, CA). Five astrocytomas, four primitive neuroectodermal tumors, and normal cerebral cortex and ependyma from autopsy brains of premature newborns, term infants, and older children served as controls. Thirteen ependymal tumors had positive nuclear staining ranging from rare tumor cells to numerous groups of cells; of these, 9 were anaplastic ependymomas and had the most staining. These studies suggest that some ependymomas arise from a pluripotential neuroglial cell. (J Child Neurol 2001;16:548-552).

Acanthameba meningoencephalitis masquerading as neurocysticercosis.

Neurocysticercosis is recognized with increasing frequency in North America, especially in the southwestern United States. The diagnosis usually is suspected in patients who present with seizures or other symptoms of a cranial mass and is considered likely in those in whom a computerized tomogram (CT) or magnetic resonance image of the head reveals a “ring-enhancing” lesion.1–6 Serologic tests are available at research, state and national laboratories to support the diagnosis. Some patients presenting with neurocysticercosis have parenchymal lesions associated with cerebral edema and intracranial hypertension.1 Such patients may be unresponsive to therapeutic intervention and die.4 In some patients with neurocysticercosis who are treated with praziquantel, an exacerbation of the inflammatory process around the lesions results in cerebral edema and clinical deterioration.7–12 In either situation the clinical course may be indistinguishable from other neurologic disorders characterized by progressive and rapid deterioration. We report a case of a fatal granulomatous amebic encephalitis in which the clinical presentation, radio-logic evaluation and cerebrospinal fluid serology all suggested neurocysticercosis.

Globoid cell leukodystrophy: comparison of neuropathology with magnetic resonance imaging

Previous imaging studies in infants with globoid cell leukodystrophy (GLD) using computed tomography have demonstrated a reduction in cerebral white matter and increased density symmetrically in the regions of the thalami, periventricular white matter, and the internal capsules. Correlation of these findings with morphologic studies at necropsy has not been made. In particular, deposition of calcium has not been described. We have evaluated two children with GLD confirmed by the absence of leukocyte galactosylceramide β-galactosidase activity using repeated magnetic resonance (MR) scans in each and correlated the imaging results with post-mortem analyses in one. Neuropathologic examination revealed abnormalities typical for GLD. In addition to the absence of normal myelination throughout cerebral and cerebellar white matter, MR images demonstrated the presence of a paramagnetic effect in the regions of the thalami, corona radiata, and centra semiovale. We have observed in histologic preparations from these areas a dense accumulation of globoid cells and some calcium, which we suggest may be responsible for producing the paramagnetic effect.

Congenital Arachnoid Cysts in Children

Congenital arachnoid cysts (CAC) are benign developmental disorders. A number of theories have been proposed to explain the origin and progression to the symptomatic stage. Management strategies range from not treating the asymptomatic cysts to craniotomy, excision of cyst wall and establishment of a communication with the adjacent subarachnoid cistern or ventricle. Other lesions may resemble CAC, and can be differentiated from CAC only by a critical review of the biopsy specimen. We have reviewed our experience with true CAC and similar lesions. Based on our experience we recommended craniotomy, excision of cyst wall and establishment of a communication with an adjacent subarachnoid cistern or ventricle as the primary procedure.

Brain metastasis: clinical characteristics, pathological findings and molecular subtyping for therapeutic implications

Metastases are the most common brain tumors especially in adults. Although they are generally considered a single disease entity which is universally fatal in patients with advanced cancer, brain metastases are remarkably heterogeneous both clinically and pathologically. As members of the multidisciplinary clinical team for the diagnosis and management of metastatic brain tumors, pathologists must be familiar not only with clinicopathologic features of brain metastases but also with any characteristic and clinically significant molecular findings. We discuss here the epidemiology, general gross and microscopic features of brain metastases with emphasis on how to differentiate them from primary brain tumors using immunohistochemistry (e.g., for identification of the primary site and differential diagnosis), and unique pathologic patterns of brain metastases (namely, dural metastasis, leptomeningeal carcinomatosis, miliary metastasis, “intravascular carcinomatosis”, and tumor-to-tumor metastasis) with their clinical and radiological characteristics. We specifically address metastatic breast and non-small cell lung cancers which are the two most commonly encountered in daily practice, with emphasis on the molecular alterations related to therapy and their clinicopathologic significance.

Acute subdural hematoma and metastatic seminoma

Acute and chronic nontraumatic subdural hematomas are rare complications of dural metastases from disseminated malignant neoplasms. We found an acute subdural hematoma in a patient with testicular seminoma metastatic to the dura.

A supratentorial, hemorrhagic, intraparenchymal epidermoid cyst

Epidermoid cysts are slow growing benign tumors that represent < 1-2% of all intracranial tumors and rarely present as supratentorial, intraparenchymal masses. We present the first report of a supratentorial, hemorrhagic, intraparenchymal epidermoid cyst with its presentation, our operative approach, post-operative course, radiographic features, and a literature review.

Late neuropathological consequences of strangulation

A case of a young man who was a victim of strangulation is presented. He arrived at the hospital in refractory status epilepticus, controlled only with intravenous pentobarbital. The initial CT scan showed mild cortical edema. Two days later, a CT scan showed diffuse cortical swelling and bilateral basal ganglia infarcts. Upon discontinuation of pentobarbital therapy, his neurological examination revealed spontaneous ventilation and a gag reflex. A CT scan 4 weeks after the insult demonstrated hypodensities in both cerebral hemispheres and hydrocephalus. EEG was isoelectric throughout his hospitalization. He survived nearly 5 months and succumbed to pneumonia. Neuropathological examination demonstrated severe encephalomalacia, multiple cystic infarcts and generalized compensatory ventriculomegaly. Microscopic examination was particularly remarkable for a pronounced gemistocytic astrocyte proliferation in the white matter. This case illustrates the long-term neuropathological consequences of severe, global hypoxia/ischemia and the paucity of intact brain required to maintain a persistent vegetative state.

Whipple disease of the central nervous system: an unusual occurrence in association with acquired immune deficiency syndrome

Whipple disease is a multisystem infectious disease caused by Tropheryma whippleii. It commonly affects the CNS and produces neurological symptoms in 10-20% of cases. Central nervous system Whipple disease occurring in patients with AIDS is extremely rare. The authors present a case of a newly diagnosed AIDS patient in whom intracranial Whipple disease was diagnosed by stereotactic brain biopsy.