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e13025 Background: In 2005 a randomized phase III study of the European Organization for Research and Treatment of Cancer and National Cancer Institute of Canada Clinical Trials Group reported an i...

The pineal gland shares a common neuroectoderm origin with the retina, and like the retina, regulates circadian rhythms through melatonin secretion. Recent expressed tag sequence (EST) analysis showed that several gene mutations, including RS1, which cause retinal degeneration, are also expressed in the pineal gland. Mutations in RS1 result in structural delamination of the neural retinal layers, leading to formation of schisis cavities in men affected with "X-linked retinoschisis" (XLRS). In this study, we evaluated RS1 expression in the rat and mouse as well as in human pineal and looked for morphological changes in the pineal of the RS1 knockout (RS1(-/Y)) mouse.We analyzed rat and mouse pineal for RS1 expression by Northern blot and in situ hybridization. RS protein, synaptophysin, S-100, and GFAP localization in the pineal of rat and mouse and RS protein in human pineal were evaluated immunohistochemically. Morphological studies were performed using transmission electron microscopy and light microscopy comparing wild-type to the RS1(-/Y) mouse.RS1 expression was detected in RNA isolated from both the pineal and retina as a single major band migrating at about 5.5 kbp in Northern blots. RS1 riboprobe in situ hybridization demonstrated message in rat and mouse pineal, and immunohistochemistry showed RS protein in pinealocytes expressing synaptophysin but not in interstitial GFAP- and S100-positive glial cells. RS protein was present in many pinealocytes in human pineal. In light and electron microscopic examination of the pineal gland from RS1(-/Y) mice none of the structural changes found in the retina, such as cavity formation and loosening of the tissue, were seen.This study demonstrates that RS protein is expressed in the pinealocytes but not in interstitial glial cells. The lack of structural abnormalities in the RS1(-/Y) mice suggests that RS serves a different function in the pineal gland than in the retina.

A 14-year-old boy with no significant medical history presented to the emergency room with a sudden onset of severe headache of 1 day’s duration. On admission, a non-contrast computed tomography (CT) of the head showed a posterior fossa hemorrhagic mass. He was immediately intubated and underwent placement of an external drainage tube. A magnetic resonance imaging (MRI) was performed, which showed a large hemorrhagic mass with upward cerebellar herniation. Despite aggressive measures, he deteriorated and was pronounced brain dead 2 days after admission. Pathological examination of the mass revealed a medulloblastoma with extensive neuronal and astrocytic differentiation. This case represents one of the few cases of rapid, hemorrhagic expansion associated with a previously undiagnosed medulloblastoma. The topic of hemorrhage due to previously unrecognized brain tumors is discussed and the value of imaging methods used in the diagnostic assessment is emphasized.

Fluorescence in situ hybridization, loss of heterozygosity testing, and comparative genomic hybridization have been used to detect NF2 gene alterations in both sporadic and neurofibromatosis type 2 (NF2)-associated central nervous system tumors. In this study, we performed chromogenic in situ hybridization (CISH) and immunohistochemistry to evaluate for NF2 gene deletion in a group of sporadic meningiomas, schwannomas, and ependymomas. Twenty-two sporadic tumors, including 9 ependymomas, 10 meningiomas, and 3 schwannomas, were studied. CISH and immunohistochemistry were performed using the NF2 gene deletion probe and NF2 polyclonal antibody. Deletion of the NF2 gene was identified in 11 (50%) tumors, including 60% (6/10) of meningiomas, 33% (3/9) of ependymomas, and 67% (2/3) of schwannomas. The remaining 11 (50%) cases were diploid. Overall, immunoexpression of NF2 protein was observed in 50% (11/22) tumors, and concordance between CISH and immunohistochemistry was observed in 73% of cases. Our results support previous observations that schwannomas and meningiomas, and to a lesser degree, ependymomas, express a high incidence of NF2 gene deletion, which supports the hypothesis that NF2 gene plays an important role in their tumorigenesis. In addition, we have validated CISH as an efficient, economic, and reliable method for routinely assessing NF2 gene deletion in these tumors.

Sporadic inclusion body myositis (IBM) is the most frequently acquired inflammatory myopathy of late adult life, yet its diagnostic criteria and pathogenesis remain poorly defined. Because effective treatment is lacking, research efforts have intensified to identify specific markers for this debilitating disorder. In this study, proteomic analysis of 4 cases of sporadic IBM was compared with 5 cases of inflammatory myopathy without clinicopathologic features of IBM to distinguish the IBM-specific proteome. Proteins were separated by 2-dimensional polyacrylamide gel electrophoresis and profiled by mass spectrometric sequencing. Expression of most proteins remained unchanged; however, 16 proteins were upregulated and 6 proteins were downregulated in IBM compared with cases of non-IBM inflammatory myopathy. These IBM-specific proteins included apolipoprotein A-I, amyloid beta precursor protein, and transthyretin, which have been associated with amyloidosis; superoxide dismutase, enolase, and various molecular chaperones indicate perturbations in detoxification, energy metabolism, and protein folding, respectively. The IBM-downregulated proteins mainly serve as carriers for muscle contraction and other normal muscle functions. We further applied Western blot and immunohistochemistry to verify the proteomic findings. This study validates proteomics as a powerful tool in the study of muscle disease and indicates a unique pattern of protein expression in IBM.

We report the rare finding of trimyelia with divergent cord pathways in a 33 5/7-week-old fetus who died shortly after spontaneous vaginal delivery.The main autopsy findings were three separate and distinct spinal cords, arising from the medulla and exiting through three separate foramina magni. The two lateral cords coursed toward each upper extremity and the medulla split into two halves that rejoined to form a central cervical cord. Further evaluation of this anomaly revealed agenesis of the cerebellar vermis and cystic dilation of the fourth ventricle. Microscopic cross-sections of the two lateral cords demonstrated well-formed central canals, white matter, and central gray with motor neurons. Sections of the abnormal mid-cervical cord demonstrated abnormally structured cord parenchyma without central canals.Some features were consistent with iniencephaly; however, defects of the occipital bone, anterior spina bifida, and shortening of the spinal cord were absent. Although agenesis of the cerebellar vermis and cystic dilation of the fourth ventricle indicate Dandy-Walker syndrome, other features such as hydrocephalus, agenesis of the corpus callosum, infundibular hamartomas, and malformations of the inferior olives or an occipital encephalocele were absent. The possible pathogenesis of this intriguing pathological entity is briefly discussed.

Oligodendroglioma is the third most common glial neoplasm and most commonly arises in the frontal lobe. It occurs in males more frequently, and the peak manifestation is during the 5th and 6th decades. Children are affected much less commonly. The clinical presentation is often of several years duration with most patients presenting with seizures, reflecting the strong predilection of this tumor to involve the cortical gray matter. Current histopathologic classification schemes recognize two main types of tumors: well-differentiated oligodendroglioma and its anaplastic variant. Less commonly, neoplastic mixtures of both oligodendroglial and astrocytic components occur and are termed oligoastrocytomas, with both well-differentiated and anaplastic forms. Surgical resection is the mainstay of initial treatment, and many patients experience a long progression-free period. Recent genotyping has revealed chromosomal loss of 1p and 19q as a genetic signature in most oligodendrogliomas, and these tumors respond favorably to chemotherapy. Hence, radiation therapy is now generally reserved for partially resected tumors and cases that failed to benefit from chemotherapy. At cross-sectional imaging, the tumor characteristically involves the cortical gray matter and frequently contains calcification. Robust enhancement is not a common feature and suggests transformation to a higher histologic grade. Advanced magnetic resonance imaging techniques and metabolic imaging play increasingly important roles in both pre- and postoperative assessment of these complex neoplasms.

BACKGROUND Published research on the clinicopathologic features of extraventricular ependymal neoplasms of the cerebral hemispheres has been scant. METHODS Thirty-two archival cases were studied to investigate the prognostic impact of clinicopathologic parameters including flow cytometry, the proliferation (Ki-67) labeling index, and p53 expression. RESULTS Among these 32 cases were 2 subependymomas, 19 ependymomas, and 11 anaplastic ependymomas. No significant gender predilection was observed, and 45% of patients were in their second or third decade of life. The left cerebral hemisphere was 1.5 times more commonly involved. On available imaging studies, lesions were often cystic, with or without a mural nodule. Tumors expressed glial fibrillary acidic protein (87%), S-100 protein (77%), cytokeratin (43%), and epithelial membrane antigen (17%). Ki-67 proliferation index paralleled tumor grade. Immunoreactivity for p53 protein was observed in the 2 cases of subependymoma, in 10 of 11 anaplastic ependymomas, and in 6 of 17 ependymomas. Flow cytometry performed in 27 tumors revealed diploidy in 20 cases and aneuploidy in 4 cases (3 anaplastic and 1 classic ependymomas), with S-phase fraction ranging from 0.2–9.7. Eleven subjects were additionally treated with radiotherapy, and 3 with chemotherapy. Follow up was available in 25 (78%) patients. CONCLUSIONS The results of the current study suggest that there is no significant relation between histopathology, Ki-67 proliferation index, p53 immunolabeling, tumor ploidy, and biologic behavior. Cancer 2005. Published 2005 by the American Cancer Society.

Glial progenitors from the brain of normal adult Sprague-Dawley rats were compared to their initiated and malignant counterparts that were isolated from apparently normal brains of animals exposed to methylnitrosourea (MNU). Fibroblast growth factor-2 (FGF-2) or platelet-derived growth factor (PDGF)-A or -B induced differentiation of normal progenitors to a pro-astrocytic or oligodendrocytic morphology, respectively, whereas the combination of these factors resulted in their terminal differentiation to oligodendrocytes and senescence. In contrast, initiated progenitors did not exit the cell cycle when stimulated with PDGF and/or FGF-2. cDNA oligoarray analysis and RT-PCR verification showed an early upregulation/ induction of growth factor/receptors, PDGF-A, PDGFR-beta, IGFR-1, IGF-1 and -2, IL-6, MEGF-5, FRAG-1, IRS-2, HSPG, and FGFR-1, followed by a late increase in the expression IGFBP-6, PDGF-alpha, FGFR-4A, c/ERB-A, and FGFR-4, 2, and 1 during the tumorigenic progression. Western blot analyses demonstrated that MNU exposure caused progressive reduction of p21 protein levels, an increase of Rb phosphorylation, activation of AKT and CDK2, and upregulation of FGF receptors. Double immunofluorescence labeling showed progressive increase in nuclear colocalization of FGFR1, 2, and 4, which peaked in malignant lines. It is postulated that transition of normal rat glial progenitors to an initiated state is driven by IGF-1 and 2, IL-6, and the upregulation of the receptors PDGFR-beta and FGFR-1, 2, and 4. Deregulation of the cell cycle in this state involves reduction of p21 protein, concomitant upregulation of CDC2, and an increase in Rb phosphorylation that favors expression and nuclear translocation of FGFR-4 and FRAG-1 and 2. These events are associated with progressive activation of AKT and RAS. Malignant transformation is enhanced by near elimination of p21 and PC3, induction of AP-1 (upregulation of JUN-B, c-JUN, FRA-1), activation of the NF-kB pro-survival pathway, and inhibition of the TGF-beta pro-apoptotic pathway possibly in response to changes in the expression of nerve growth factor (NGF) I-A and NGFI-B. These data demonstrate that the events leading to malignancy in the rat brain in response to MNU treatment are to a great extent similar to those described for secondary glial malignancies in humans.

Pilocytic astrocytoma is the most common pediatric central nervous system glial neoplasm and the most common pediatric cerebellar tumor. This tumor has a noteworthy benign biologic behavior that translates into an extremely high survival rate-94% at 10 years-that is by far the best of any glial tumor. Most patients present in the first 2 decades, and clinical symptoms and signs are usually of several months duration and directly related to the specific location of the tumor. The t cerebellum, optic nerve and chiasm, and hypothalamic region are the most common locations, but the tumor can also be found in the cerebral hemisphere, ventricles, and spinal cord. Surgical resection is the treatment of choice for all tumors, except for those involving the optic pathway and hypothalamic region, which may be treated with radiation therapy and chemotherapy. Cross-sectional imaging often demonstrates a classic appearance: a cystic mass with an enhancing mural nodule. Less common appearances are quite nonspecific. Surrounding vasogenic edema is rarely present, and this feature provides a valuable clue to the correct diagnosis. Accurate interpretation of imaging studies plays an essential role in directing treatment of these tumors, particularly when they arise in the optic pathway of patients with neurofibromatosis type 1. Disseminated disease and recurrence are extremely rare.

✓ Erdheim—Chester disease (ECD) is a rare systemic histiocytic disease. The authors present a case report detailing the presentation and treatment of a 26-year-old man diagnosed with seizures and a well-circumscribed temporoparietal mass that had been demonstrated on imaging studies. Both preoperative and intraoperative diagnoses were consistent with a low-grade astrocytic neoplasm. Subsequent pathological examination indicated a histiocytic proliferation positive for CD68 and factor VIII, and negative for CD1a and S100, with Touton giant cells characteristic of ECD. This case represents the first isolated occurrence of intracranial ECD and its potential to mimic glial neoplasms.

Peripheral nerve pathology encompasses a complex array of disease processes that are poorly understood. This article provides a substrate for communication between pathologists and radiologists who are involved in the diagnosis and treatment of patients with peripheral neuropathy. The article is organized into sections on normal histology, routine morphologic techniques used in the study of peripheral nerve, and the basic disease patterns, followed by a brief discussion of selected neuropathies.

Oligodendrogliomas (OGs) are rare in children and have not been well characterized from a molecular viewpoint. In adults, losses on chromosomes 1p and/or 19q are common in "oligodendroglial" neoplasms and are highly associated with chemosensitivity and greater length of survival, especially in the anaplastic category. We have analyzed the 1p/19q status of pediatric OGs and compared it with similar alterations in adult OGs. Paraffin sections from 26 pediatric OGs (21 WHO Grade II OGs: 2 anaplastic oligodendrogliomas [AOGs]: and 3 mixed oligo-astrocytomas [MOA]) were retrieved. Fluorescence in situ hybridization (FISH) was performed using probes spanning the 1p32 and 19q13 regions. In tumors from children 0 to 9 years of age (n = 15), none had any deletions on 1p or 19q, but 2 had polysomies for 1p and/or 19q. All are alive and 4 have had recurrences. In tumors from children > 9 years, losses were identified on chromosomes 1p (5/11; 45%) and/or 19q (3/11; 27%), but to a much lesser extent than that observed in adult OGs. Tumors from 6 older patients also had polysomies for 1p and/or 19q. Although the majority of the older children are alive, 4 had recurrences. Curiously, 2 of the older children with AOGs had combined losses and polysomies on 1p and 19q, but responded poorly to treatment and died within a year. We conclude that alterations on 1p or 19q are infrequent in pediatric compared to adult OGs and are virtually absent in OGs presenting in the first decade of life. Compared to adults therefore, different genetic pathways are likely involved in the pathogenesis of most pediatric OGs. Genomic screening on a larger series is clearly indicated to delineate the unique molecular characteristics of these rare pediatric tumors.

Transforming growth factor (TGF)-β is thought to play an important role in the pathogenesis of malignant gliomas. There are several anti-TGF-β strategies that are currently being explored in early clinical trials. Yet, it has remained a challenge to identify tumor or patient profiles that reliably predict potential benefit from anti-TGF-β therapies. Moreover, there is little contemporary in vivo data on the differential expression of TGF-β/Smad pathway activity in glioblastoma. Here we studied 64 newly diagnosed and 16 recurrent glioblastomas for the expression of TGF-β1-3, platelet-derived growth factor (PDGF)-B, and plasminogen activator inhibitor (PAI)-1 mRNA by RT-PCR and for levels of TGF-β1-3 protein, pSmad2 and pSmad1/5/8 by immunohistochemistry. Among TGF-β isoforms, TGF-β1 mRNA was the most abundant, whereas TGF-β3 mRNA showed the lowest levels. TGF-β1-3 mRNA expression among each other was strongly correlated, as was the expression of TGF-β1-3 mRNA and of the TGF-β1-3 target genes, PDGF-B and PAI. The TGF-β2 isoform was overexpressed at the protein level compared to the expression of the TGF-β1 or TGF-β3 isoforms. TGF-β2 and TGF-β3 protein levels correlated well, whereas the comparison of the other TGF-β isoforms did not. Immunohistochemical analysis of pSmad2 and pSmad1/5/8 showed heterogeneous expression among tumor samples and a positive correlation. Based on protein data, pSmad1/5/8 correlated with TGF-β1, but other correlations were not observed. Expression levels of mRNA or protein targets of the TGF-β/Smad pathway activity were not associated with survival, confirmed for mRNA expression in the TCGA. This study provides important new information on the biology of the TGF-β pathway, demonstrating that all TGF-β isoforms are expressed in glioblastoma and that the transcriptional targets of the TGF-β/Smad pathway are collectivly controlled, which was best assessed by RT-PCR at mRNA expression levels. Our data support the enrichment of glioblastoma patients with TGF-β-driven tumors for future clinical trials targeting TGF-β.

Clinic for Neurology, University Medical Centre Gottingen, Gottingen, Germany; Department of Neuroimmunology, University Medical Centre Gottingen, Gottingen, Germany; Department of Trauma Surgery, University Medical Centre Gottingen, Gottingen, Germany; Department of Neuropathology, University Medical Centre Gottingen, Gottingen, Germany; Friedrich-Baur-Institute, University of Munchen, Munchen, Germany; Department of Neurology, University of Halle, Halle, Germany; Neuroimmunology Unit, Dept. of Pathophysiology, University of Athens Medical School, Athens, Greece; Department of Rheumatology and Clinical Immunology, University Medical Centre Freiburg, Freiburg, Germany

Twenty-one cases of nonneoplastic pineal cyst are presented. The patients were 13 women and 8 men, with a median age of 33 years. Sixteen patients were symptomatic. Symptomatic cysts had an average size of 16.5 mm. In most cases, symptoms and signs were related to increased intracranial pressure, cerebrospinal fluid obstruction, neuroophthalmologic dysfunction, brainstem and cerebellar compression, and mental status changes. Uncommon clinical presentations in three cases were related to increased cyst size caused by hemorrhage, sudden death, and postural syncope and loss of consciousness. Imaging studies showed a uniform hypodense or hypointense, nonenhancing pineal mass with occasional peripheral calcification and associated with hydrocephalus, aqueductal compression, tectal deformity, and hemorrhage within the cavity, in decreasing order of frequency. Fourteen patients underwent open cyst resection. Histologically, the intact lesions show a unilocular or multilocular cavity, surrounded by a wall comprised of variable amounts of glial tissue, remnants of pineal gland, and an external fibrous capsule. Follow-up information showed 12 patients alive and well without recurrence between 26 and 144 postoperative months. One patient who underwent stereotactic drainage had a recurrence. One symptomatic patient who did not have surgery died suddenly of causes related to the cyst. The present study supports the role of surgical excision for the treatment of symptomatic pineal cysts to obtain adequate tissue for diagnosis and relief of symptoms. The use of histochemical and immunohistochemical studies may prove useful in the distinction of these lesions with astrocytomas and cystic pineal parenchymal tumors.

Controversy exists regarding the pathogenetic relationship of mesial temporal sclerosis (MTS) to epileptogenesis. Some investigators view hippocampal sclerosis as the primary cause of temporal lobe epilepsy, whereas others interpret the changes to be the result of chronic seizure activity. The present autopsy-based study attempts to clarify the etiologic relationship between mesial temporal sclerosis and epilepsy. To investigate the assumption that bilateral MTS is more likely to be the result of chronic seizure activity associated with a seizure focus outside the hippocampus, two subject groups were identified. The first group comprised 43 patients who had no extrahippocampal pathology and were classified as having primary epilepsy. The second group comprised 35 patients who, had identifiable extrahippocampal pathology and were classified as having secondary epilepsy. Fifteen of the 35 cases of secondary epilepsy also had MTS; seven of these were unilateral and eight were bilateral. Of the 43 cases with primary epilepsy, only one had MTS, and it was unilateral. Significantly more cases of primary epilepsy than secondary epilepsy had no MTS (p < 0.001), suggesting that both unilateral and bilateral forms of MTS occur with greater frequency in subjects with seizure foci outside the hippocampus. These results also suggest that unilaterality of MTS does not exclude an extrahippocampal cause.

Although there is general agreement that certain morphologic subtypes of ependymoma are benign, the biologic behavior of other ependymal neoplasms is poorly understood and not clearly related to conventional histopathologic criteria. The absence of universally accepted standards has prompted the search for more objective biologic markers. Telomerase is an RNA-containing enzyme associated with immortality in proliferating stem cells and many tumors. We investigated the proliferative activity of 26 ependymomas as determined by MIB-1 immunolabeling and compared the results with the in situ expression of human telomerase RNA (hTR) and WHO tumor grade. The study included 9 WHO grade I ependymomas (6 subependymomas and 3 myxopapillary ependymomas), 13 WHO grade II ependymomas, and 4 anaplastic (WHO grade III) ependymomas. The proliferation index (PI) and telomerase RNA expression were significantly increased in grade III ependymomas (p < 0.0001 for PI and p = 0.0015 for hTR). In these tumors, the PI and hTR expression were highly correlated (p = 0.0001). Of note, a single case designated grade II showed both increased proliferative activity and the highest hTR expression detected in this series of ependymal neoplasms. Our results suggest that the PI and hTR expression may be important biologic markers, independent of other histopathologic criteria of tumor grade. Future studies examining the correlation of MIB-1 cell kinetics and hTR expression with clinical parameters in selected ependymoma subtypes are needed to determine the prognostic relevance of these markers.

Adenomatous neoplasms with histologically benign papillary architecture arising at the interface of the posterior cranial fossa dura and the petrous temporal bone are locally aggressive tumors capable of extensive destruction. Patients may present with intracranial extension of this neoplasm and signs or symptoms of involvement of contiguous neurotologic structures. These signs may manifest sensorineural hearing loss, vestibular dysfunction, facial paresis, and facial hypesthesia or paresthesia. These tumors share a common origin from the mucosa of the endolymphatic sac and have clinical, radiologic, and histopathologic features that distinguish them from other tumors occurring in the petrous temporal bone and cerebellopontine angle. These tumors warrant distinction as a distinct clinicopathologic entity. The case of a 48-year-old man with an endolymphatic sac tumor showing petrous temporal bone destruction and involvement of the cerebellopontine angle and review of the current literature on these tumors is presented.

Autoimmune necrotizing myopathies (ANM) represent a well-recognized entity among the so-called idiopathic inflammatory myopathies (IIMs), which also comprise dermatomyositis (DM), polymyositis (PM), sporadic inclusion body myositis (sIBM) and non-specific myositis. The diagnosis of these IIMs is established on the basis of specific clinical symptoms, results derived from muscle biopsy and ancillary data, such as creatine kinase (CK) levels, electromyography (EMG) and modern imaging techniques. Myositis-associated and myositis-specific autoantibodies play an important role and may prove to be clues for understanding details of the pathogenesis of these conditions, which to date remain largely unknown. ANMs probably represent a heterogeneous group of diseases all of which are characterized by the striking presence of necrotic fibres on muscle biopsy. However, additional morphological features as well as certain autoantibodies (e.g. SRP or HMGCR auto-antibodies) may be helpful to define subgroups of ANM. Subclassification of ANMs and definition of specific syndromes with precise and characteristic immunological features is a subject of intense research, especially since clinical trials with anti-inflammatory agents or so called ’biologicals’ should follow universally defined and accepted criteria. We present molecular and morphological data of subgroups within the spectrum of autoimmune necrotizing myopathies.

Ependymomas, which comprise 5% of central nervous system tumors, have not been extensively characterized genetically. The p53 tumor suppressor gene is frequently mutated in human cancer, and is important in the pathogenesis of other central nervous system (CNS) tumors. Chromosomal DNA corresponding to the p53 tumor suppressor gene was amplified by the polymerase chain reaction (PCR) from 31 archival ependymoma specimens. DNA was screened for the presence of p53 mutations by single strand conformational polymorphism (SSCP) analysis; samples with altered mobility were further tested for the presence of mutation by direct DNA sequence analysis. Of the 31 ependymomas tested, one contained a detectable DNA sequence change in the p53 gene. Sequencing revealed a silent mutation in exon 6, at codon 213, which represents a known p53 sequence polymorphism. These findings suggest that in contrast to many other human cancers, p53 mutation is not important in the pathogenesis or progression of ependymomas.

Background Adenoma of the retinal pigment epithelium (RPE) is a rare intraocular tumor that can simulate other pigmented tumors such as choroidal melanoma. We report a case of non-pigmented adenoma of the RPE initially diagnosed as choroidal hemangioma. Case report A 42-year-old woman presented to Kurume University Hospital in November 1992 with an orange-yellow tumor nasal to the optic disc in the left fundus. The tumor was 9.0 × 9.0 mm in diameter, 6.0 mm thick, and was characterized by high intensity on T1-weighted magnetic resonance imaging (MRI), low intensity on T2-weighted MRI, and enhancement on gadolinium MRI. Fluorescein angiography revealed early hypofluorescence and late hyperfluorescence of the tumor and retinal feeder vessels. By April 1996, exudate had developed around the tumor margins. The patient was treated with external beam radiation therapy (20 Gy) in July 1996, but the tumor did not diminish in size. Subsequently, she developed extensive loss of vision due to total retinal detachment. Accordingly, her left eye was enucleated in June 2005 because of severe ocular pain due to absolute glaucoma. Histopathological examination indicated that the tumor was contiguous with the normal surrounding RPE and was composed of cords and tubules of mostly non-pigmented spindle-shaped cells with round to oval nuclei and a small amount of cytoplasm containing melanin granules. The tumor cells were immunoreactive for vimentin, S-100 protein, and cytokeratin 18. The final diagnosis was adenoma of the RPE. Conclusion Adenoma of the retinal pigment epithelium may be associated with incompetent vessels leading to serous retinal detachment and extensive visual loss, and may exhibit clinical characteristics similar to choroidal hemangioma.

Most pineal region masses are malignant germ cell neoplasms that occur in young male patients. The most common is a germinoma, which is a homogeneous mass with signal intensity and attenuation similar to those of gray matter; the mass engulfs a densely calcified pineal gland. Teratomas are multilocular heterogeneous masses containing lipid areas. Other types of pineal region masses include choriocarcinoma, endodermal sinus tumor, and embryonal carcinoma. Pineal parenchymal neoplasms are usually either pineocytomas or pineoblastomas, which may "explode" preexisting pineal calcifications. Unlike the germinomas, they have no sexual predilection and may be seen in patients who are 20 years of age or older. Although the correct histologic diagnosis may be suggested with a careful evaluation of the morphologic features, attenuation, and signal intensity characteristics, very few of these tumors have a truly pathognomonic imaging pattern. Thus, histologic verification is necessary for most pineal region masses that appear to be neoplastic.

Objective Recent studies indicate that WT1 and Bcl2 protein are detected in melanocytic lesions of the skin. We examined, for the first time, WT1 and Bcl2 expression in a variety of conjunctival melanocytic lesions to evaluate their diagnostic utility compared with other melanocytic markers. Methods Protein expression and localization of WT1 and Bcl2 were studied by means of immunolabeling and semiquantification in 123 conjunctival melanocytic lesions (71 benign nevi, 21 atypical nevi, 11 primary acquired melanosis, and 20 malignant melanomas). Ancillary immunohistochemical studies were performed with Bcl2, S100, HMB45, and Melan A antibodies. Results WT1 showed a graded increase in expression in lesions with increasing atypia. Higher mean numbers of WT1 -positive cells correlated with increasing atypia in melanocytes. In all cases, Bcl2 expression was positive and more robust than was S100, HMB45, or Melan A expression. WT1 and HMB45 frequently showed diffuse and strong staining in atypical nevi, primary acquired melanosis with atypia, and malignant melanomas compared with benign lesions. Conclusions Bcl2 is a highly sensitive immunohistochemical marker for melanocytic tumors of the conjunctiva; HMB45 and WT1 staining distinguishes benign from malignant lesions. Clinical Relevance Our results show that HMB45 and WT1 immunolabeling is helpful in the evaluation of conjunctival melanocytic lesions. Accordingly, we recommend the development of an immunohistochemical panel to classify these lesions.

Hemangioblastomas are low-grade, capillary rich neoplasms of the cerebellum and spinal cord that can occur sporadically or in the setting of Von Hippel-Lindau syndrome. The present study analyzed the utility of proliferation potential in differentiating hemangioblastoma from RCC metastatic to the central nervous system using a MIB-1 (Ki-67) labeling index and assessment of expression of the RNA component of telomerase. Immunohistochemical analysis for epithelial membrane antigen (EMA) and MIB-1 was performed on paraffin-embedded sections of 27 hemangioblastomas and 5 RCC metastatic to the central nervous system. All but one hemangioblastoma demonstrated low or negative MIB-1 immunoreactivity, while 4 of 5 RCC metastases had moderate or high labeling indices. Telomerase RNA expression was assessed in 10 hemangioblastomas and in all 5 metastatic RCC by in Situ hybridization. All 10 hemangioblastomas demonstrated a lack of expression of telomerase RNA, while all 5 metastatic RCCs showed moderate to strong expression. Our results suggest that the MIB-1 labeling index is useful in differentiating hemangioblastoma from metastatic RCC and assessment of telomerase expression can also provide novel information on the difference in growth potential of these tumors.

1512 Background: Glioblastoma multiforme (GBM) is a high grade primary brain neoplasm associated with a median survival of less than a year. Historically, one-third of patients seem to benefit from treatment with alkylating chemotherapy. This minority may correspond to a population with decreased levels of active O6-methylguanine- methyltransferase enzyme (MGMT). MGMT repairs tumor DNA damaged by chemotherapy, allowing continued replication after exposure to treatment. Patients with low tumor MGMT activity may be more likely to respond to alkylating treatment. Hypermethylation of the MGMT promoter region leads to decreased transcription of the enzyme and is associated with improved outcome in GBM patients treated with radiation and alkylating chemotherapy. Methods: We studied a patient cohort with newly diagnosed GBM registered on Southwest Oncology Group protocol S0001, a phase III randomized, two arm clinical trial investigating an inhibitor of MGMT (O6-benzylguanine, O6BG). Both groups received standard radiation and BCNU (carmustine). The experimental group additionally received O6BG. We determined polymerase chain reaction (PCR) methylation status of the promoter region of MGMT in 88 patients with adequate tissue samples. In 41 cases, we were able to obtain successful PCR results. Results: 28 of 41 samples (68%) were found to be unmethylated and 13 of 41 (32%, 95% c. i. 18% to 50%) were methylated. Patients with methylated MGMT had a median survival of 12.6 months (95% c.i. of 7.8–15.8 months). Patients with unmethylated MGMT had a median survival of 10.6 months (95% c.i. of 8.7–12.0 months). Median progression-free survivals were 4.5 and 3.1 months respectively, for the methylated and unmethylated groups. Conclusions: This result is consistent with prior studies which showed that approximately two-thirds of patients express MGMT, and accordingly, are resistant to alkylating agents. The subgroup of patients without promoter methylation may be more likely to benefit from treatment with O6BG. Analysis of MGMT promoter methylation status per study treatment group, and correlation with median survival and progression-free survival will be presented. No significant financial relationships to disclose.

OBJECTIVE AND IMPORTANCE: Spinal nerve root hemangioblastomas are rare and are reported mainly in patients with von Hippel-Lindau (VHL) syndrome. The pathogenesis of so-called nonfamilial lesions is virtually unknown. We discuss, mainly from a molecular perspective, a unique patient with sporadic, recurrent hemangioblastomas restricted to spinal nerve roots. CLINICAL PRESENTATION: A 53-year-old man who had had a surgically corrected lumbosacral meningomyelocele presented on at least three occasions during a 17-year period with multifocal capillary hemangioblastomas involving spinal nerve roots. On each occasion, tumors appeared on a different nerve root, with the majority located in the midcervical segments. The patient had no clinical features or family history of VHL syndrome. TECHNIQUE: To obtain a clearer understanding of the pathogenesis of this unusual case and its relationship to VHL syndrome, molecular analysis of the VHL gene was performed by use of complete sequence analysis and loss of heterozygosity studies on deoxyribonucleic acid derived from the patient's blood leukocytes and three separately resected hemangioblastomas. CONCLUSION: Germ-line molecular analysis performed on all three exons in the VHL gene coding region did not indicate that any mutations were present. Loss of heterozygosity analysis of deoxyribonucleic acid from the three hemangioblastoma resections showed normal heterozygosity in the 3p25-26 region. Complete VHL gene sequence analysis did not demonstrate a somatic mutation in the coding region of the VHL gene in any of the three tumors, thereby supporting the loss of heterozygosity data that a molecular event directly involving the VHL gene may not be the causative factor in their tumorigenesis.

OBJECTIVE AND IMPORTANCE Spinal nerve root hemangioblastomas are rare and are reported mainly in patients with von Hippel-Lindau (VHL) syndrome. The pathogenesis of so-called nonfamilial lesions is virtually unknown. We discuss, mainly from a molecular perspective, a unique patient with sporadic, recurrent hemangioblastomas restricted to spinal nerve roots. CLINICAL PRESENTATION A 53-year-old man who had had a surgically corrected lumbosacral meningomyelocele presented on at least three occasions during a 17-year period with multifocal capillary hemangioblastomas involving spinal nerve roots. On each occasion, tumors appeared on a different nerve root, with the majority located in the midcervical segments. The patient had no clinical features or family history of VHL syndrome. TECHNIQUE To obtain a clearer understanding of the pathogenesis of this unusual case and its relationship to VHL syndrome, molecular analysis of the VHL gene was performed by use of complete sequence analysis and loss of heterozygosity studies on deoxyribonucleic acid derived from the patient's blood leukocytes and three separately resected hemangioblastomas. CONCLUSION Germ-line molecular analysis performed on all three exons in the VHL gene coding region did not indicate that any mutations were present. Loss of heterozygosity analysis of deoxyribonucleic acid from the three hemangioblastoma resections showed normal heterozygosity in the 3p25–26 region. Complete VHL gene sequence analysis did not demonstrate a somatic mutation in the coding region of the VHL gene in any of the three tumors, thereby supporting the loss of heterozygosity data that a molecular event directly involving the VHL gene may not be the causative factor in their tumorigenesis.

BACKGROUND Mesenchymal chondrosarcomas arising in the central nervous system are extremely rare. Morphologic features have not been found to correlate reliably with prognosis. METHODS Eight intracranial and five intraspinal mesenchymal chondrosarcomas were reviewed with regard to location, treatment, and long term follow-up data. The histopathologic and immunohistochemical results, including Ki-67 nuclear staining frequency, were critically reviewed, and deoxyribonucleic acid content was analyzed by flow cytometry. RESULTS Microscopically, all 13 cases were remarkably similar. Immunoreactivity in the small cell component included vimentin in 100%, and cytokeratin and glial fibrillary acidic protein in 25% of cases. S-100 immunoreactivity was noted in the cartilaginous component of 100% of cases, and in rare cells in the small cell component along the interface. Flow cytometry of the eight tumors studied revealed a diploid pattern in six, aneuploidy in two, and a wide range of S-phase fractions (0–36.5%). CONCLUSIONS Review of the literature and the findings of the current series indicates that mesenchymal chondrosarcomas presenting in the brain and spinal cord pursue a progressive course that correlates most reliably with extent of surgical resection. This limited retrospective study also suggests that survival may be shorter for those patients with a high S-phase fraction and a high Ki-67 staining frequency. Cancer 1996;77:1884-91.

Serum samples from 121 patients in whom malignant disease had been diagnosed, were assayed for precipitins to fungal isolates from leukemia-associated environments. Control sera were from age-, sex-, and race-matched patients with no history of malignant disease. Sera from 36 (30%) malignancy patients and seven (6%) controls yielded a precipitin band to an aflatoxin-producing Aspergillus flavus isolate from a leukemia-associated house (x2 = 222, p less than 0.05%). No significant numbers of precipitins were obtained to either of the other fungal isolates from that and another such house. Although A. fumigatus has frequently been incriminated as a source of infection in patients with malignancy, only 9% of malignancy patients had a precipitin response to it, as did 1.6% of controls. Also, the presence of the precipitins to A. flavus was not connected with past radiation or immunosuppressive therapy. However, among patients with precipitins to A. fumigatus there was a higher death rate in the year following the study. Precipitins to A. flavus may be related to heavy environmental exposure possibly leading to aflatoxin exposure which may contribute to development of malignancy though immunosuppressive effects.

Microglial activation is a hallmark of most neurodegenerative disorders, yet it is not clear if it plays beneficial or deleterious roles. Zhu et al. provide evidence for a general protective role of microglia in the pathogenesis of prion diseases., Microglial activation is a hallmark of most neurodegenerative disorders, and is particularly conspicuous in prion diseases. However, the role of microglia, which function as both primary immune effector cells and professional phagocytes in the central nervous system, remains contentious in the context of neurodegeneration. Here, we evaluated the effect of microglial depletion/deficiency on prion pathogenesis. We found that ganciclovir-mediated microglial ablation on tga20/CD11b-thymidine kinase of Herpes simplex virus (HSVTK) cerebellar organotypic cultured slices markedly aggravated prion-induced neurotoxicity. A similar deterioration of disease was recapitulated in in vivo microglial depletion in prion-infected tga20/CD11b-HSVTK mice. Additionally, deficiency of microglia in interleukin 34 knockout (IL34−/−) mice again resulted in significantly augmented proteinase K–resistant prion protein deposition and accelerated prion disease progression. These results provide unambiguous evidence for a general protective role of microglia in prion pathogenesis.