The expanding spectrum of herpesvirus infections of the nervous system

Herpesviruses cause various acute, subacute, and chronic disorders of the central (CNS) and peripheral (PNS) nervous systems in adults and children. Both immunocompetent and immunocompromised individuals may be affected. Zoster (shingles), a result of reactivation of varicella zoster virus (VZV), is the most frequent neurologic complication. Other neurological complications include encephalitis produced by type I herpes simplex virus (HSV-1), and less frequently HSV-2, as well as by VZV and cytomegalovirus (CMV). Acute meningitis is seen with VZV and HSV-2, and benign recurrent meningitis with HSV-2. Combinations of meningitis/ encephalitis and myelitis/radiculitis are associated with Epstein Barr Virus (EBV); myelitis with VZV, CMV, EBV, and HSV-2; and ventriculitis/encephalitis with VZV and CMV. Brainstem encephalitis due to HSV and VZV, and polymyeloradiculitis due to CMV are well documented. HHV-6 produces childhood exanthem subitum (roseola) and febrile convulsions. Immunocompetent and immunocompromised hosts manifest different incidences and patterns of herpesvirus infections. For example, stroke due to VZV-mediated large vessel disease (herpes zoster ophthalmicus) occurs predominantly in immunocompetent hosts, while small vessel disease (leukoencephalitis) and ventriculitis develop almost exclusively in immunocompromised patients. EBV-associated primary CNS lymphomas also are restricted to immunosuppressed individuals. Recent large CSF PCR studies have shown that VZV, EBV, and CMV more frequently produce meningitis, encephalitis, or encephalopathy in immunocompetent hosts than was formerly realized. We review herpesvirus infections of the nervous system and illustrate the expanding spectrum of disease by including examples of a 75-year-old male on steroid treatment for chronic lung disease with fatal HSV-2 meningitis and an 81-year-old male with myasthenia gravis, long-term azathioprine use, and an EBV-associated primary CNS lymphoma.

Brain metastases from hepatocellular carcinoma in US patients

Hepatocellular carcinoma (HCC) is a disease on the rise in the United States, due to the epidemic of hepatitis C-induced liver disease. Better chemotherapy options, aggressive surgery, and liver transplantation have led to improved patient survival and an increase in late-appearing, distant metastases from HCC. Brain metastases, although formerly thought of as rare manifestations of HCC, may be more likely to come to clinical and pathological attention than extrahepatic metastases in other sites since they often produce clinical symptoms that necessitate neurosurgical intervention and metastasis removal. In addition, brain metastases from HCC are frequently associated with mass-producing hemorrhage, further requiring evacuation. Hence, pathologists are relatively more likely to encounter brain metastases from HCC as surgical specimens than metastases from HCC to some other common sites of spread, such as bone, lymph nodes, or adrenal. Brain metastases from HCC are being increasingly documented in areas of the world with high endemic rates such as Asia, but thus far have only very rarely been reported in patients native to the United States. We describe our institution's experience with three Caucasian US males, two with hepatitis C as risk factors, who developed metastatic HCC to the brain. We expect clinicians and pathologists will encounter more patients with HCC and extrahepatic metastases, particularly those to brain, in the near future.

CSF findings in 250 patients with serologically confirmed West Nile virus meningitis and encephalitis

OBJECTIVE

To provide a large, comprehensive evaluation of the CSF findings in patients with serologically confirmed West Nile virus (WNV), CNS disease, and their correlation with outcome.

METHODS

CSF samples from 334 WNV-infected hospitalized patients were analyzed. Information was available and extracted from the medical records of 250 of these patients, and CSF parameters correlated with clinical and epidemiologic features of disease (e.g., patient age, sex, outcome).

RESULTS

Patients with meningitis had a mean of 226 cells/mm3, and those with encephalitis had a mean of 227 cells/mm3. Three percent of meningitis patients and 5% of encephalitis patients had fewer than 5 cells/mm3, and approximately 8% of both groups had more than 500 cells/mm3. Patients with meningitis had a mean of 41% neutrophils, and those with encephalitis had 45%. Forty-five percent of meningitis patients and 37% of encephalitis patients had at least 50% neutrophils in their initial CSF specimen. Neither the mean percent neutrophils nor their distribution differed significantly between groups. Forty-seven percent of encephalitis patients and 16% of meningitis patients had CSF protein of 100 mg/dL or greater (p < 0.01). Although specific CSF parameters, including nucleated cell count and protein concentration, correlated significantly with outcome, multivariate analysis suggested that their total predictive value was modest. Age was an additional predictor of outcome independent of CSF variables in all patients.

CONCLUSIONS

Serologically confirmed West Nile virus meningitis and encephalitis produce similar degrees of CSF pleocytosis and are frequently associated with substantial CSF neutrophilia. Patients with encephalitis have higher CSF protein concentrations and are more likely to have adverse outcomes, including admission to long-term care facilities or even death after their acute illness. CSF findings were only a modest predictor of disease outcome, with patient age adding important independent prognostic information.

Glioblastomas in the older old

CONTEXT

Recent studies have identified fundamental biological differences in the effects of epidermal growth factor receptor (EGFR) amplification on survival in older versus younger patients with glioblastoma multiforme (GBM). Cell cycle labeling indices have also been found to be inordinately high in older GBM patients and may contribute to the known adverse prognosis in this cohort. However, testing has not been conducted on significant numbers of patients of very advanced age, in whom these features might be expected to emerge as even more significant factors.

OBJECTIVE

To assess EGFR amplification status and MIB-1 indices in patients with GBM who are older than 75 years.

DESIGN

We identified 20 patients (female-male ratio, 11:9; 11 aged 75-79 years and 9 aged 80-87 years) and studied tumor tissue samples with immunohistochemistry for cell cycle labeling index and by fluorescence in situ hybridization for EGFR amplification. Survival data were obtained from the Colorado Tumor Registry.

RESULTS

Mean MIB-1 index was high (24.8%), but individual indices did not correlate with survival. EGFR amplification was detected in 25% of cases, with gain of chromosome 7 in all but one of the remaining patients. Ninety-five percent of patients manifested EGFR amplification and/or polysomy of chromosome 7. Heterogeneity was found within a given tumor, with 10% to 60% of cells showing gain of chromosome 7. Overall patient survival was poor (mean, 4.6 months), but was significantly longer in those with EGFR gene amplification (mean, 8.3 months; median, 10.5 months) versus those without (mean, 3.2 months; median, 2.0 months) (P = .04).

CONCLUSION

The presence of EGFR amplification is a significant predictor of survival time in older old patients.

A 71-year-old male with 4 decades of symptoms referable to both central and peripheral nervous system

May 2005. Combined demyelination of the central and peripheral nervous system is an uncommon disorder and has been referred to by many appellations. We present the case of a 71-year-old man with a progressive nervous system disorder beginning in his 30s. The diagnosis in life was unclear, but had over the years been variously considered to be Guillain-Barrè Syndrome (GBS), Friedreich ataxia, or multiple sclerosis (MS). At autopsy old CNS demyelination consistent with MS was found as well as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with onion bulb formation in hypertrophic nerves. Microscopic examination showed some onion bulb formation in the CNS as well as in peripheral nerves. The nosology of these disorders is discussed and relevant animal models briefly reviewed.

Progressive multifocal leukoencephalopathy complicating treatment with natalizumab and interferon beta-1a for multiple sclerosis

A 46-year-old woman with relapsing-remitting multiple sclerosis died from progressive multifocal leukoencephalopathy (PML) after having received 37 doses of natalizumab (300 mg every four weeks) as part of a clinical trial of natalizumab and interferon beta-1a. PML was diagnosed on the basis of the finding of JC viral DNA in cerebrospinal fluid on polymerase-chain-reaction assay and was confirmed at autopsy. Nearly every tissue section from bilateral cerebral hemispheres contained either macroscopic or microscopic PML lesions. There was extensive tissue destruction and cavitation in the left frontoparietal area, large numbers of bizarre astrocytes, and inclusion-bearing oligodendrocytes, which were positive for JC virus DNA on in situ hybridization.

Insights into meningioangiomatosis with and without meningioma: a clinicopathologic and genetic series of 24 cases with review of the literature

Meningioangiomatosis (MA) is a rare seizure-associated lesion of presumed hamartomatous or developmental origin. It is occasionally combined with a neoplasm, most commonly meningioma (MA-M). In the current study, we examined 24 cases (14 pure MA, 10 MA-M) using immunohistochemistry for merlin, protein 4.1 B, progesterone receptor (PR), and MIB-1, as well as FISH for NF2 and 4.1B gene dosages. Nine cases of MA-M (90%) had gene deletions (NF2/4.7B), protein losses (merlin/protein 4.1B), and/or PR positivity, with a similar or identical phenotype in both components. No PR positivity or gene deletions were seen in pure MAs, though merlin and/or protein 4.1B were immunonegative in six cases. Our data suggest that in most MA-Ms, the MA component is neoplastic, likely representing an exuberant perivascular pattern of spread from the meningioma, rather than an underlying hamartoma. This pattern of spread may be facilitated by meningiomas that are predominantly leptomeningeal or intracerebral in origin. It remains important to distinguish this pattern from true brain invasion, given the more ominous prognostic significance of the latter. In contrast, most perivascular spindled cells of pure MA are genetically and immunohistochemically similar to non-neoplastic meningothelial cells, consistent with current histogenetic theories.

Lymphomatosis cerebri as a cause of white matter dementia

Primary central nervous system lymphoma most often presents as a solitary, isolated lesion in immunocompetent patients. Rarely, the disease presents as a diffuse, infiltrating condition without formation of a cohesive mass, a pattern called lymphomatosis cerebri. We present 3 immunocompetent individuals who developed rapidly progressive dementia. Magnetic resonance imaging features mimicked other disorders of white matter and prompted preoperative diagnoses of Binswanger's disease (subcortical ischemic vascular dementia), unknown leukoencephalopathy, viral infection, or infiltrating glioma. Neuropathologic examination at biopsy (Poon T, Matoso I, Tchertkoff V, Weitzner I Jr, Gade M. CT features of primary cerebral lymphoma in AIDS and non-AIDS patients. J Comput Assist Tomogr . 1989;13:6-9) and autopsy (Schwaighofer BW, Hesselink JR, Press GA, Wolf RL, Healy ME, Berthoty DP. Primary intracranial CNS lymphoma: MR manifestations. Am J Neuroradiol . 1993;10:725-9) demonstrated nonnecrotic, diffusely infiltrating, large-cell B-cell lymphoma of white matter, with relative sparing of gray matter, and without significant leptomeningeal involvement or bulky periventricular disease at autopsy. Microglial and astrocytic reactions, but only subtle myelin pallor, were evident as individual tumor cells permeated the entire brain and spinal cord, albeit with considerable variation in cell density. Individual tumor cells could be identified from the optic nerve to spinal cord, documenting the "whole-brain" nature of the disease. CD20 immunostaining was necessary to fully appreciate the extent of individual lymphoma cell percolation through the white matter. The neurobehavioral deficits manifested by these patients demonstrate that lymphomatosis cerebri is an additional neoplastic cause of white matter dementia and can be added to the growing list of disorders responsible for this syndrome.

Naturally acquired West Nile virus encephalomyelitis in transplant recipients: clinical, laboratory, diagnostic, and neuropathological features

BACKGROUND

In the 2003 West Nile virus (WNV) epidemic, Colorado reported more WNV cases than any other state, including an unprecedented number in organ transplant recipients.

METHODS

Physicians caring for transplant recipients hospitalized with naturally acquired WNV encephalitis provided data to characterize the clinical symptoms, results of diagnostic studies, and outcomes.

RESULTS

Eleven transplant recipients were identified (4 kidney, 2 stem cell, 2 liver, 1 lung, and 2 kidney/pancreas). Seven were directly admitted to 1 of the 2 hospitals in the study, and 4 were referred to 1 of these centers from regional hospitals. All but 1 patient had a prodrome typical of WNV encephalitis in nonimmunosuppressed patients. Ten patients developed meningoencephalitis, which in 3 cases was associated with acute flaccid paralysis. One patient developed acute flaccid paralysis without encephalitis. Six patients had significant movement disorders including tremor, myoclonus, or parkinsonism. All patients had cerebrospinal fluid pleocytosis and WNV-specific IgM in the cerebrospinal fluid and/or serum. Cerebrospinal fluid cytologic studies (n = 5) showed atypical lymphocytes, some resembling plasma cells; however, flow cytometry (n = 3) showed that cells were almost exclusively of T-cell (not B-cell or plasma cell) lineage. Magnetic resonance images of the brain were abnormal in 7 of 8 tested patients, and electroencephalograms were abnormal in 7 of 7, with 2 showing periodic lateralized epileptiform discharges. Nine of 11 patients survived infection, but 3 had significant residual deficits. One patient died 17 days after admission, and autopsy findings revealed severe panencephalitic changes with multifocal areas of necrosis in the cerebral deep gray nuclei, brainstem, and spinal cord as well as diffuse macrophage influx in the periventricular white matter. A second patient died of complications of WNV encephalitis 6 months after hospital admission.

CONCLUSIONS

Naturally acquired WNV encephalitis in transplant recipients shows diagnostic, clinical, and laboratory features similar to those reported in nonimmunocompromised individuals, but neuroimaging, electroencephalography, and autopsy results verify that these patients develop neurological damage at the severe end of the spectrum.

The effects of toluene on the central nervous system

In recent decades the organic solvent toluene (methylbenzene) has emerged as one of the best-studied neurotoxins. Long-term and intense exposure to toluene vapors in humans who abuse spray paint and related substances has led to the recognition that toluene has a severe impact on central nervous system myelin. Chronic toluene abuse produces a devastating neurological disorder, of which dementia is the most disabling component. The clinical syndrome, toluene leukoencephalopathy, can be detected by a combination of characteristic symptoms and signs, detailed neurobehavioral evaluation, and brain magnetic resonance imaging. In this paper, we consider the impact of toluene abuse on our society, describe the specific neurobehavioral deficits in toluene leukoencephalopathy, review the spectrum of neuroimaging findings in patients with this disorder, summarize the teratogenic effects of toluene in both humans and animal models, and offer possible explanations for the range of neuropathological damage seen in brains of individuals who chronically abuse toluene.

Proximal nerve root spinal hemangioblastomas: presentation of three cases, MR appearance, and literature review

BACKGROUND

Hemangioblastomas (HBLs) are relatively uncommon tumors of uncertain histogenesis usually located in the cerebellum or spinal cord. Much less frequently they are identified in extramedullary locations including the filum terminale, proximal nerve roots, or even distal nerves of the peripheral nervous system (PNS). PNS cases not only present diagnostic challenges but also raise interesting questions regarding the common cell of origin for these CNS and PNS neoplasms. Few studies have detailed the neuroimaging characteristics of the rare extramedullary variants.

METHODS

Neuroimaging and intraoperative findings of three recent cases of proximal nerve root HBLs are described. The English language literature on extramedullary HBLs is reviewed and discussed, particularly in regards to magnetic resonance (MR) findings and association with von Hippel-Lindau Syndrome (VHL).

RESULTS

All 3 of our cases had prominent vessels present within the subarachnoid space on MR scans and all lesions enhanced. All were of intermediate or mildly decreased signal intensity on the T1-weighted images before contrast and were either iso- or hyperintense to spinal cord on the T2-weighted images. Two had probable cystic areas on MR, and all had cystic areas on histologic evaluation.

CONCLUSION

These neuroimaging characteristics can serve to distinguish HBLs from the more common benign nerve sheath tumors with which they are most frequently confused. Less than half of all extramedullary HBLs are diagnosed in patients with known VHL. It is important to consider HBLs in the differential diagnosis, as they are vascular and have the propensity for causing significant blood loss at surgery.

Synovial excrescences and cysts of the spine: clinicopathological features and contributions to spinal stenosis

Synovial cysts occur throughout the body and are generally benign lesions with limited clinical consequences. Juxtafacet cysts of the spine, in contrast, often press on a nerve root as it exits in the foramen, causing radiculopathy. Synovial tissue that emanates from the facet joint but extends medially, is an additional important cause of spinal stenosis. Over the past 5 years, neurosurgeons at our institution have operated on a large number of patients with back pain, with removal of abnormal synovial tissues. Histological examination of these tissues distinguishes the different types of pathologic processes responsible for producing symptoms. Juxtafacet cysts may be either mucin-filled ganglion cysts devoid of cyst lining or true synovial cysts with watery content and lined by synovial cells. Ganglion cysts arise in degenerated ligament at the facet joint, and occasionally within synovial stroma. Synovial cysts arise within synovium and, unlike synovial cysts in the extremities, have a thick wall containing granulation tissue, numerous histiocytes and giant cells. This hyperplastic, irritated synovium of the spine, which we term "synovial excrescences", is voluminous and this reactive part overshadows the cystic portion of the lesion in most instances. Iron pigment deposition and inflammation are mild to absent, making synovial excrescences different from pigmented villonodular synovitis. Synovial excrescences of the spine are an important cause of spinal stenosis, predominantly in elderly patients. Surgical removal of excrescences protruding into the spinal canal provides prompt and durable relief of symptoms, usually without the need for extensive bony laminectomy or spinal fusion. Several patients in our study had both spinal ganglion cysts and synovial excrescences, suggesting common risk factors for both lesions.

Gamna-Gandy Bodies in Surgical Neuropathology Specimens: Observations and a Historical Note

Gamna-Gandy (G-G) bodies are classically defined as spheroidal yellow-brown foci consisting of dense fibrous tissue and collagenous fibers encrusted with iron pigments and calcium salts. These siderotic nodules were first described in the spleen early in the twentieth century and for a short time were considered to be caused by fungal infection due to the presence of unusual "bamboo-like and articulated" fibers in the lesions that vaguely mimicked mycelia forms. This notion was proven to be incorrect in the 1930s and G-G bodies are now considered to result from organization of small hemorrhages. Although originally reported in splenomegaly, G-G bodies are well-recognized findings in atrial myxomas where they form linear arrays of mineral-encrusted fibers, often at the edge of resolving hemorrhages. They rarely have been reported in lymph nodes, thymoma, thyroid adenoma, and renal cell carcinoma. Curiously, published examples of G-G bodies in central nervous system (CNS) neoplasms or vascular malformations have not appeared, despite the known tendency for bleeding, even recurrent episodes of bleeding, in several types of these lesions. Since 1999 I have accrued all the examples of G-G bodies that I have observed in my practice of surgical neuropathology. These cases are presented here and the historical aspects of the entity are reviewed.

Gliomatosis cerebri: neurobehavioral and neuropathological observations

BACKGROUND

Gliomatosis cerebri is a rare neoplasm in which individual neoplastic cells diffusely permeate the brain; a cohesive tumor mass may appear late in the disease course, or not at all. The diagnosis can be made either at autopsy or premortem by combining biopsy and neuroimaging findings to demonstrate involvement of more than two lobes of the brain. Extensive hemispheric white matter and corpus callosum infiltration is characteristic, with lesser spread to subcortical and cortical gray matter. Whereas this pattern of localization can be predicted to cause significant disturbances of higher function, the neurobehavioral profile of gliomatosis cerebri patients has not been well described.

METHOD

Three patients with gliomatosis cerebri had detailed neurobehavioral assessment, and one had neuropsychological testing early in the disease. Neuropathological investigation focused on the localization of the neoplasm, the correlation between extent of myelin and axon damage with tumor cell density, and the histogenesis of the tumor.

RESULTS

The patient with neuropsychological testing had impaired executive function and verbal memory retrieval that reflected bifrontal and left temporal white matter tumor involvement seen on neuroimaging. In the other cases, apathy and fatigue progressed to severe dementia in association with bihemispheric white matter infiltration. Myelin and axon stains and myelin stains showed relative preservation of white matter architecture with severity of damage paralleling increased tumor cell density. Immunostaining for TP53 was found in a high percentage of tumor nuclei in two of three cases, suggesting overlapping features between gliomatosis cerebri and diffuse astrocytomas.

CONCLUSIONS

Subtle cognitive and emotional alterations antedate the florid dementia that develops later in the course of gliomatosis cerebri. Clinical, neuroimaging, and neuropathological data suggest that white matter is damaged directly by the tumor and its associated mild edema, although infiltration of subcortical and cortical gray matter also occurs to a variable extent. Strong TP53 immunostaining in gliomatosis cerebri suggests a commonality with diffuse fibrillary astrocytomas that also often show TP53 staining. Gliomatosis cerebri can be considered a cause of white matter dementia resulting from preferential neoplastic disruption of white matter tracts.

Neoplasms involving the central nervous system in the older old

Geriatric cancer patients present special challenges for clinicians. Few large series have been published in the last 20 years on the types of neoplasms that involve the central nervous system (CNS) in older individuals. To review types of neoplasms involving the central CNS that are currently being encountered by pathologists and neurosurgeons, we identified from our databases for the years 1992-2002, inclusive, patients 75 years or older who had symptomatic lesions requiring neurosurgical interventions. Retrospective characterization of tumors by immunohistochemistry, in situ hybridization, and fluorescence in situ hybridization was performed whenever possible and relevant to tumor type. Neurosurgical procedures (n=125) on 119 patients were identified; 90 patients were diagnosed as having neoplasms, with clot evacuation or infections being the most frequent non-neoplastic conditions necessitating surgery. Tumor types included glioblastomas (36 patients), meningiomas (16), pituitary adenomas (12), lymphomas or other hematological malignancies (8), anaplastic gliomas (5), metastases (6), head and neck malignancies with direct intracranial extension (3), and other miscellaneous tumor types (4). Compared with older literature series, we encountered a larger number of elderly patients with CNS lymphomas and fewer who came to surgery for CNS metastatic disease. In the "older old", glioblastomas are the most frequent symptomatic tumors necessitating surgical intervention. Glioblastomas in this aged cohort display the signature features of the small cell phenotype (62%), high cell cycle labeling indices (mean MIB-1-labeling index=25.1%), and either amplification of epidermal growth factor receptor or gain of chromosome 7 by fluorescence in situ hybridization (93% of assessable cases).

Hematological neoplasms with first presentation as spinal cord compression syndromes: a 10-year retrospective series and review of the literature

CONTEXT

The epidural space is a well-known, albeit uncommon, location for lymphomatous involvement, estimated to occur in less than 3% of all systemic lymphomas. Initial presentation of the patient with disease in this site (i.e. primary spinal epidural lymphoma) has been considered to be "rare". When it has been reported, many studies have emphasized the occurrence of aggressive lymphomas with a poor prognosis.

DESIGN

A 10-year retrospective search of our files generated 7 patients who presented initially with back pain, incontinence and/or lower extremity weakness, and by neuroimaging studies were found to have masses causing spinal cord compression syndromes necessitating neurosurgical intervention.

RESULTS

The 7 patients included 4 males and 3 females with thoracic and lumbar epidural masses. Tumor types included high-grade non-Hodgkin lymphoma, B cell type (n = 4), indolent B cell lymphoma (n = 1), nodular sclerosing Hodgkin lymphoma (n = 1) and plasmacytoma (n = 1). Advanced disease (stage 4) was subsequently identified in all 7 patients. Despite this, survival varied greatly with therapy, from 3 weeks to almost 6 years, underscoring the need for correct classification of the lymphoma in order to optimize chemotherapeutic choices. The epidural space was the site of presentation of disease in 4% of all lymphomas diagnosed at our institution.

CONCLUSIONS

Combining all reports in the literature, epidural presentation of lymphoma is not rare. Epidural lymphomas are distinct from both primary central nervous system lymphomas and from primary dural lymphomas. A broad range of systemic hematological tumor types can present as epidural masses. A full work-up for lymphoma classification may only be possible from the tissues received at the time of the neurosurgical decompression or biopsy procedure.

Giant cell glioblastoma and pleomorphic xanthoastrocytoma show different immunohistochemical profiles for neuronal antigens and p53 but share reactivity for class III beta-tubulin

CONTEXT

Giant cell glioblastoma multiforme (GCGBM) and pleomorphic xanthoastrocytoma (PXA) are clinically, radiographically, and histologically distinct tumors of the central nervous system. However, they share features of gross circumscription, reticulin deposition, lymphocytic infiltrates, and prominent populations of tumor giant cells. Neuronal antigens have been detected in the neoplastic cells of PXAs, but to our knowledge have not been studied previously in GCGBMs. While TP53 is mutated in most GCGBMs, a feature usually paralleled by strong immunostaining of the protein, the expression pattern of PXAs has not been extensively studied.

OBJECTIVES

To compare the immunoprofiles of GCGBM and PXA with regard to neuronal antigens and p53 and to evaluate the potential diagnostic utility of such a panel.

DESIGN

Archival paraffin sections of 9 GCGBMs and 9 PXAs were immunostained for class III beta-tubulin, neuronal nuclear antigen, neurofilament protein, synaptophysin, glial fibrillary acidic protein, and p53.

RESULTS

Giant cell glioblastomas were strongly immunoreactive for class III beta-tubulin and glial fibrillary acidic protein, but showed only rare staining for the other neuronal polypeptides. In contrast, PXAs usually showed at least focal staining of individual tumor cells for most of the neuronal antigens tested. Tubulin was strongly positive in tumor giant cells and in smaller neoplastic cells of both tumor types. Double-immunolabeling revealed distinct populations of tumor cells that expressed either glial fibrillary acidic protein or tubulin and dual-labeling of individual cells in GCGBM and PXA. Strong p53 staining was observed in many tumor cells in 5 of 8 GCGBMs tested, while staining for this antigen was negative or focally positive in 6 of 8 PXAs examined.

CONCLUSIONS

Giant cell glioblastoma multiforme and PXA show distinct patterns of immunoreactivity for neuronal antigens and p53 that may be useful diagnostically in difficult cases or in limited samples. These results provide further evidence of neuronal antigen expression by PXA.

Gamma interferon transduced 9L gliosarcoma. Cytokine gene therapy and its relevance to cellular therapy with alloreactive cytotoxic T lymphocytes

In earlier studies, we demonstrated that intratumoral infusions of alloreactive cytotoxic T lymphocytes (aCTL), sensitized to the major histocompatibility complex (MHC) antigens of the host, effectively retarded the intracranial growth of Fischer 9L gliosarcoma. We further demonstrated that continuous in vitro exposure to gamma-interferon (gammaIFN) upregulates MHC on 9L gliosarcoma cells and that they were better targets of anti-Fischer aCTL. We hypothesized that the efficacy of cellular therapy with aCTL could be further improved by in situ transduction of the tumor with retroviral vectors coding for gammaIFN, which would generate continuous secretion of the cytokine and maintain upregulated MHC expression by the tumor cells. 9L gliosarcoma and Herpes simplex virus thymidine kinase (tk) transductants of those cells were transduced with a retrovirus carrying the murine gammaIFN gene. By limiting dilution, clones of these cells, designated 9Lgamma 7, 9Lgamma tk8, and 9Lgamma tk10, which produced similar levels of gammaIFN (383-411 ng gammaIFN/10(6) cells/24 h) were isolated. The production of gammaIFN by one clone, 9Lgamma 7, was stable when monitored over 6 weeks in vitro. The clones also demonstrated upregulated MHC class I expression, and the tk-transduced clones maintained their sensitivity to ganciclovir. Compared to the wildtype cells, 9Lgamma 7 had approximate 6- and 1.5-fold increases in the relative antigen densities of MHC I and II, respectively. Addition of exogenous gammaIFN to 9Lgamma 7 cultures did not significantly increase the MHC expression. In cytotoxicity assays, 9Lgamma 7 cells, or 9Lgamma 7 incubated with exogenous gammaIFN, were better targets of aCTL than the parental 9L cells. The growth rate of 9Lgamma-transduced cells was decreased compared to the wildtype cells both in vitro and in vivo. Proliferation studies with transwell plated 9L, 9Lgamma 7, and 9Lgamma tk10 cells in various combinations revealed that the secreted cytokine itself caused a decrease in proliferation. However, the transduced cells exhibited a much reduced growth rate, which likely was a consequence of redirected metabolic activity of the cells. In vivo growth of the 9L and 9Lgamma 7 tumors in rat brains given identical inoculums similarly demonstrated significantly reduced 9Lgamma 7 tumor volumes at various timepoints, indicative of slower growth of the gammaIFN-producing tumors.

Survivin in glioblastomas. Protein and messenger RNA expression and comparison with telomerase levels

CONTEXT

Survivin is a novel inhibitor of apoptosis that acts via a pathway independent of bcl-2. Little is known about its distribution in brain tumors or how it correlates with other biomarkers of malignancy, such as telomerase, an enzyme that plays a critical role in cellular immortalization and cancer biology.

OBJECTIVES

To assess survivin protein expression in gliomas and to compare expression with that of telomerase.

DESIGN

Immunohistochemical staining for survivin protein expression was performed using an antibody developed in our laboratory. Quantitative survivin messenger RNA (mRNA) levels were assessed by reverse transcriptase-polymerase chain reaction. In selected cases, survivin results were compared with quantitative telomerase values analyzed by polymerase chain reaction-based telomerase repeat amplification protocol (TRAP) assay. Twenty-five tumor tissue samples from 16 cases of glioblastoma multiforme (GBM; including multiple tissue samples in 6 patients), 2 grade II gliomas, 4 grade III gliomas, and 3 control temporal lobectomy specimens were studied.

RESULTS

Nuclear immunoreactivity for survivin protein and survivin mRNA were detectable in most glioma samples, regardless of grade. Glioblastoma multiforme demonstrated moderate protein expression and survivin mRNA levels compared to epithelial malignancies previously tested in our laboratory. Although the association of survivin mRNA with the levels of telomerase within the GBM cases did not reach statistical significance, most GBMs also expressed survivin. The quantitative score for survivin mRNA was higher in GBMs than in grade II and III gliomas (P =.02), after accounting for multiple specimens per patient.

CONCLUSIONS

Quantitative survivin mRNA analysis, but not immunohistochemistry, distinguished GBMs from lower grade gliomas. Mechanisms that promote both cell proliferation (telomerase expression) and cell survival (survivin expression) are often activated in GBMs.

Intracalvarial cholesterol granulomas--clinicopathologic correlates of three cases

Cholesterol granulomas (CGs) are tumor-like lesions seldom encountered by neuropathologists. CGs develop in reaction to localized hemorrhage, often occurring in bony sites with possible impaired drainage of blood and blood products. The most common bony location is the petrous apex, although orbital, frontal sinus, and maxillary sinus sites have been reported. We compare and contrast three recent cases seen at our institution that illustrate the spectrum of clinical, radiographic, and pathologic features that can be seen with these mass lesions. One case demonstrated the unique pathological features of Gamma-Gandy body formation, epithelioid histiocytes heavily encrusted with iron pigments, and extensive tophi. The latter most likely represented aggregates of calcium pyrophosphate crystals associated with extensive iron deposition.

Central nervous system apoptosis in human herpes simplex virus and cytomegalovirus encephalitis

Central nervous system (CNS) specimens from 10 immunocompetent patients with herpes simplex encephalitis (HSE) and 3 infants with congenital cytomegalovirus (CMV) encephalitis were analyzed to determine whether apoptosis is a feature of CNS injury in these patients. Apoptotic neurons and glia were detected in significant numbers in acute HSE and CMV encephalitis. Occurring predominantly in areas of productive viral infection, apoptosis appeared to result from direct viral injury to neurons and was not dependent on inflammatory T cell responses. In contrast to patients with acute cases, patients with late sequelae of HSE or CMV had no detectable virus and minimal neuronal or glial apoptosis, regardless of the degree of inflammation. This is the first demonstration of apoptotic neuronal death in humans with HSE. These results suggest that neuronal apoptosis is an important contributing factor to acute CNS injury and may serve as a novel therapeutic target in these patients.

Progressive multifocal leukoencephalopathy and apoptosis of infected oligodendrocytes in the central nervous system of patients with and without AIDS

CONTEXT

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system (CNS) caused by JC virus (JCV) that occurs in immunocompromised patients. Demyelination of the CNS is a consequence of virus-induced killing of oligodendrocytes, although the exact mechanism of cell death is unknown.

OBJECTIVE

To examine archival autopsy and surgical pathologic specimens from 8 patients with PML, including 6 patients with human immunodeficiency virus (HIV)-associated PML and 2 patients with non-HIV-associated PML, for evidence of apoptosis.

DESIGN

Apoptotic cells were identified by TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end in situ labeling) or immunohistochemical detection of activated caspase 3. The JCV-infected cells were identified by in situ hybridization for viral transcripts or immunohistochemical analysis for JCV T antigen.

RESULTS

Apoptosis of JCV-infected oligodendrocyte apoptosis was a prominent feature in all cases of both HIV- and non-HIV-associated PML. There were no differences between number or distribution of apoptotic cells identified by TUNEL or immunohistochemical analysis for activated caspase 3. Bizarre astrocytes were occasionally positive for JCV but were not apoptotic. Neurons, astrocytes, macrophages, and oligodendrocytes remote from lesions were neither apoptotic nor JCV infected.

CONCLUSIONS

Our study demonstrates that apoptosis occurs in oligodendrocytes associated with demyelinated lesions of patients with both HIV-associated and non-HIV-associated PML. There were no differences in degree, location, or type of infected or apoptotic cells between patients with HIV-associated and non-HIV-associated PML. The extent of apoptosis did not correlate with the presence or intensity of host inflammatory response. Accumulation of viral particles in nuclei of infected cells made it difficult to identify morphologic changes in the nucleus typically associated with apoptosis.