Hyperintense cortical signal on magnetic resonance imaging reflects focal leukocortical encephalitis and seizure risk in progressive multifocal leukoencephalopathy.

OBJECTIVE: To determine the frequency of hyperintense cortical signal (HCS) on T1-weighted precontrast magnetic resonance (MR) images in progressive multifocal leukoencephalopathy (PML) patients, its association with seizure risk and immune reconstitution inflammatory syndrome (IRIS), and its pathologic correlate. METHODS: We reviewed clinical data including seizure history, presence of IRIS, and MR imaging scans from PML patients evaluated at our institution between 2003 and 2012. Cases that were diagnosed either using cerebrospinal fluid JC virus (JCV) polymerase chain reaction, brain biopsy, or autopsy, and who had MR images available were included in the analysis (n=49). We characterized pathologic findings in areas of the brain that displayed HCS in 2 patients and compared them with isointense cortex in the same individuals. RESULTS: Of 49 patients, 17 (34.7%) had seizures and 30 (61.2%) had HCS adjacent to subcortical PML lesions on MR images. Of the 17 PML patients with seizures, 15 (88.2%) had HCS compared with 15 of 32 (46.9%) patients without seizures (p=0.006). HCS was associated with seizure development with a relative risk of 4.75 (95% confidence interval=1.2-18.5, p=0.006). Of the 20 patients with IRIS, 16 (80.0%) had HCS compared with 14 of 29 (49.3%) patients without IRIS (p=0.04). On histological examination, HCS areas were associated with striking JCV-associated demyelination of cortical and subcortical U fibers, significant macrophage infiltration, and a pronounced reactive gliosis in the deep cortical layers. INTERPRETATION: Seizures are a frequent complication in PML. HCS is associated with seizures and IRIS, and correlates histologically with JCV focal leukocortical encephalitis.

GM1-gangliosidosis in American black bears: clinical, pathological, biochemical and molecular genetic characterization.

G(M1)-gangliosidosis is a rare progressive neurodegenerative disorder due to an autosomal recessively inherited deficiency of lysosomal ß-galactosidase. We have identified seven American black bears (Ursus americanus) found in the Northeast United States suffering from G(M1)-gangliosidosis. This report describes the clinical features, brain MRI, and morphologic, biochemical and molecular genetic findings in the affected bears. Brain lipids were compared with those in the brain of a G(M1)-mouse. The bears presented at ages 10-14 months in poor clinical condition, lethargic, tremulous and ataxic. They continued to decline and were humanely euthanized. The T(2)-weighted MR images of the brain of one bear disclosed white matter hyperintensity. Morphological studies of the brain from five of the bears revealed enlarged neurons with foamy cytoplasm containing granules. Axonal spheroids were present in white matter. Electron microscopic examination revealed lamellated membrane structures within neurons. Cytoplasmic vacuoles were found in the liver, kidneys and chondrocytes and foamy macrophages within the lungs. Acid ß-galactosidase activity in cultured skin fibroblasts was only 1-2% of control values. In the brain, ganglioside-bound sialic acid was increased more than 2-fold with G(M1)-ganglioside predominating. G(A1) content was also increased whereas cerebrosides and sulfatides were markedly decreased. The distribution of gangliosides was similar to that in the G(M1)-mouse brain, but the loss of myelin lipids was greater in the brain of the affected bear than in the brain of the G(M1) mouse. Isolated full-length cDNA of the black bear GLB1 gene revealed 86% homology to its human counterpart in nucleotide sequence and 82% in amino acid sequence. GLB1 cDNA from liver tissue of an affected bear contained a homozygous recessive T(1042) to C transition inducing a Tyr348 to His mutation (Y348H) within a highly conserved region of the GLB1 gene. The coincidence of several black bears with G(M1)-gangliosidosis in the same geographic area suggests increased frequency of a founder mutation in this animal population.

An unusual cause of stroke in a 55-year-old woman.

A 55-year-old woman presented with acute onset ataxia and right-sided dysmetria. Magnetic resonance imaging (MRI) confirmed clinical suspicion of stroke. She was found to have middiastolic murmur which led to urgent echocardiogram demonstrating left atrial myxoma. She underwent prompt surgical resection. Cardiac myxoma is a very rare cause of stroke. The presentation can be varied and diagnosis can be often missed. Early surgical intervention is a definitive treatment. Our case is unique and underlines importance of eliciting accurate physical signs at bedside.

Multicolored stain-free histopathology with coherent Raman imaging.

Conventional histopathology with hematoxylin & eosin (H&E) has been the gold standard for histopathological diagnosis of a wide range of diseases. However, it is not performed in vivo and requires thin tissue sections obtained after tissue biopsy, which carries risk, particularly in the central nervous system. Here we describe the development of an alternative, multicolored way to visualize tissue in real-time through the use of coherent Raman imaging (CRI), without the use of dyes. CRI relies on intrinsic chemical contrast based on vibrational properties of molecules and intrinsic optical sectioning by nonlinear excitation. We demonstrate that multicolor images originating from CH(2) and CH(3) vibrations of lipids and protein, as well as two-photon absorption of hemoglobin, can be obtained with subcellular resolution from fresh tissue. These stain-free histopathological images show resolutions similar to those obtained by conventional techniques, but do not require tissue fixation, sectioning or staining of the tissue analyzed.

Oncogenic EGFR signaling cooperates with loss of tumor suppressor gene functions in gliomagenesis.

Glioblastoma multiforme (GBM) is a highly lethal brain tumor for which little treatment is available. The epidermal growth factor receptor (EGFR) signaling pathway is thought to play a crucial role in GBM pathogenesis, initiating the early stages of tumor development, sustaining tumor growth, promoting infiltration, and mediating resistance to therapy. The importance of this pathway is highlighted in the fact that EGFR is mutationally activated in over 50% of GBM tumors. Consistent with this, we show here that concomitant activation of wild-type and/or mutant (vIII) EGFR and ablation of Ink4A/Arf and PTEN tumor suppressor gene function in the adult mouse central nervous system generates a fully penetrant, rapid-onset high-grade malignant glioma phenotype with prominent pathological and molecular resemblance to GBM in humans. Studies of the activation of signaling events in these GBM tumor cells revealed notable differences between wild-type and vIII EGFR-expressing cells. We show that wild-type EGF receptor signals through its canonical pathways, whereas tumors arising from expression of mutant EGFR(vIII) do not use these same pathways. Our findings provide critical insights into the role of mutant EGFR signaling function in GBM tumor biology and set the stage for testing of targeted therapeutic agents in the preclinical models described herein.

Nodular bilateral amygdala degeneration in demented individuals.

Among more than 2,050 brains in our Alzheimer disease brain banks, we came across three brains with well-demarcated indurated white-yellow nodules in the amygdalas. Microscopically, these nodules were composed of numerous lipid-laden macrophages located in the central region surrounded by an eosinophilic hyaline-like material with minimal reactive gliosis in the periphery. Neurons within these lesions had a normal appearance but were moderately decreased in number. Beta-amyloid, tau and alpha-synuclein immunostaining revealed no abnormal deposits within the nodules. The three patients had long histories of dementia (one linked to a presenilin-1 mutation). The neuropathological diagnoses were Alzheimer disease in two of them and an unclassified tauopathy with argyrophilic grains in the third. In conclusion, the pathogenesis of these lesions is uncertain. We favor that the degeneration has some relationship to the underlying dementing disease, either secondary to deafferentation or an alteration in metabolic demand, perhaps related to the bi-directional anatomical and functional connections that exist between the amygdala and the hippocampus or less likely as a primary event.

Adjuvant Gamma Knife radiosurgery following surgical resection of brain metastases: a 9-year retrospective cohort study.

Given the potential morbidity of whole brain radiation therapy (WBRT), there has been an increasing trend to defer WBRT and deliver Gamma Knife stereotactic radiosurgery (GKS) to cerebral metastatic lesions. We analyzed our experience delivering GKS to the tumor cavity following surgical resection of brain metastases and compared our results to patients receiving WBRT after surgical resection of a metastatic lesion. We performed a retrospective review of patients undergoing surgical resection of at least one brain metastasis between December 1999 and December 2008. Both univariate and multivariate Cox proportional hazards regression were utilized to analyze the influence of various prognostic factors on survival. Twenty-five patients had a metastatic lesion resected followed by adjuvant GKS to the resection cavity while another 18 had surgical resection followed by WBRT. Aside from a disparity in gender distribution (72% of GKS patients were female while women only constituted 28% of the WBRT group), no significant differences existed between groups. The median survival for patients receiving GKS was 15.00 months as compared to 6.81 months among those receiving WBRT (P = 0.08). Univariate Cox regression analysis identified the number of metastases (HR 1.65, 95% CI 1.07-2.54, P = 0.02) and regional recurrence (RR 5.23, 95% CI 1.78-15.38, P = 0.003) as poor prognostic factors. Multivariate regression analysis showed that regional recurrence (HR 5.17, 95% CI 1.69-15.78, P = 0.004) was again strongly associated with worse survival. Although limited by the retrospective nature of our study and lack of some clinical measures, patients undergoing GKS to the resection cavity had a trend towards longer median survival.

Electron microscopic findings in skin biopsies from patients with Danon disease.

Danon disease is a rare lysosomal disorder. It is due to deficiency of lysosomal-associated protein-2. In human LAMP-2 gene is located at chromosome region Xq24. Danon disease is characterized by hypertrophic cardiomyopathy, skeletal myopathy, mental retardation and retinopathy. To date, the morphological characterization of Danon disease has been limited to endomyocardial and skeletal muscle biopsies. In the current study we demonstrated that electron microscopy of a more accessible tissue, skin biopsies, is a useful method in the diagnosis of Danon disease.

Morphological findings of extraocular myopathy with chronic progressive external ophthalmoplegia.

Mitochondrial diseases are a large group of disorders resulting from mutations of nuclear DNA (nDNA) and mitochondrial DNA (mtDNA). Patients present clinically with multiple manifestations, including myopathies and multiple system disorders. Establishing a specific diagnosis often requires extensive clinical and laboratory evaluation. In this study of 2 adult patients with presumptive mitochondrial disease, the authors have identified distinctive morphological changes in medial rectus muscle biopsies that confirm the diagnosis of chronic progressive external ophthalmoplegia (CPEO). These findings demonstrate the usefulness of electron microscopy using medial rectus muscle in the diagnosis of adult patients with a slowly progressive course of mild skeletal weakness and CPEO.

Convexity dural cavernous malformation with intradural and extradural extension mimicking a meningioma: a case report.

BACKGROUND: Dural-based cavernous malformations are rare and have been more commonly described in the middle fossa. Fewer than 20 cases outside of the middle fossa have been reported and they often mimic more commonly found lesions such as meningiomas or hemangiopericytomas. CASE DESCRIPTION: We describe the unusual case of a right frontal convexity dural cavernous malformation with intradural and extradural components as well as erosion through the calvarium. The patient underwent a right frontal craniotomy and en-bloc resection of the mass. Final pathologic interpretation confirmed a cavernous malformation that had eroded through the calvarium. CONCLUSION: Dural-based cavernous malformations are a rare entity, but should be considered in the differential diagnosis of atypical appearing dural-based lesions and soft subgaleal masses. If atypical features are present, further radiographic investigations should be undertaken. To our knowledge, this is the only reported case of a dural-based cavernous malformation eroding through the calvarium and presenting initially as a soft scalp mass.

Oncocytic adrenal cortical tumor with cytoplasmic inclusions and hyaline globules.

Adrenal cortical tumors, particularly oncocytic tumors, have been reported to contain a variety of intracytoplasmic and intramitochondrial inclusions. Oncocytic cortical tumors can also morphologically mimic pheochromocytomas. We report an unusual, partially oncocytic cortical neoplasm with nesting architecture, intranuclear inclusions, and hyaline globules reminiscent of pheochromocytoma, together with numerous, small, brightly eosinophilic, periodic acid-Schiff-positive cytoplasmic inclusions and typical cytoplasmic lipid droplets. Ultrastructural study revealed oncocytes containing numerous mitochondria with intramitochondrial crystals and lipid droplets. Immunohistochemistry and immunoblots were utilized to further characterize the tumor. Immunohistochemistry demonstrated immunoreactivity of both the eosinophilic inclusions and the hyaline globules for adipose differentiation-related protein (ADRP), which is one of a group of proteins associated with storage of neutral lipids in many cell types. Immunoblots confirmed the presence of ADRP and demonstrated an imbalance between ADRP and perilipin, another neutral lipid-associated protein, in tumor tissue compared to normal adrenal cortex. The findings suggest that mitochondrial dysfunction in oncocytic cortical tumors may lead to abnormal processing of proteins related to the lipid-storing functions of the adrenal cortex, resulting in unusual cytoplasmic inclusions and extracellular globules resembling the globules in pheochromocytomas. The finding of ADRP as a constituent of inclusions in adrenal cortical tumors has not been previously reported.

Electron microscopic findings in skin biopsies from patients with infantile osteopetrosis and neuronal storage disease.

Infantile osteopetrosis with neuronal storage disease is a rare lysosomal storage disorder. It is an autosomal recessive disease that is associated with mutations in the OSTM1 and chloride channel ClCN-7genes. So far mutations in the OSTM1 gene have been identified in only 8 patients. To date, the clinical and morphological features of nine patients with infantile osteopetrosis with neuronal storage have been reported, but no ultrastructural findings of skin have been described in these patients. Skin biopsy is a cost-effective tool for the diagnosis of lysosomal storage disease. The purpose of this report is to define the ultrastructure of affected cells seen in skin biopsies of 2 boys whose mutation of OSTM1 has been characterized. The children presented in infancy with severe osteopetrosis and neurological deficiencies whose predominant symptoms were marked cerebral atrophy, decreased myelinization, and severe central nervous system involvement. Because of the difficulties in distinguishing this disorder from some lysosomal storage diseases such as mucopolysaccharidosis that have both neurological and skeletal abnormalities, the authors elected to examine skin biopsies from these children. Ultrastructural examination revealed the presence of swollen unmyelinated axons containing spheroids, reduced numbers of myelinated axons, and the presence of secondary lysosomes in Schwann cells containing lipofuscin. This study demonstrates that electron microscopy of skin biopsy is a useful diagnostic method to identify patients with clinical features of osteopetrosis with neuronal storage disease.

Rheumatoid meningitis: a rare complication of rheumatoid arthritis.

We present a case of a 60-year-old Caucasian woman with a 23-year history of rheumatoid arthritis, who presented with a 2-week history of headache and cognitive/behavioural changes. On the basis of clinical features, radiology, laboratory data and meningeal biopsy, a diagnosis of rheumatoid meningitis was performed. High-dose intravenous methylprednisolone was used as initial treatment followed by oral prednisone. The patient's symptoms improved and repeat MRI scans confirmed resolution of the meningeal lesions. The clinical diagnosis of rheumatoid meningitis is difficult, but it must be considered in patients with long-standing rheumatoid arthritis presenting with neurological symptoms. Glucocorticoids or other immunomodulatory therapy are the mainstay of treatment.

Sterile brain abscess due to juvenile xanthogranuloma: DWI characteristics.

Juvenile xanthogranuloma (JXG) is a disorder of non-Langerhans cell histiocytosis that usually displays as a self-limiting course in children. Rare systemic involvement implies poor prognosis. Although conventional and spectroscopic magnetic resonance imaging (MRI) findings of JXG in CNS have been described, diffusion imaging of intracranial JXG has not been reported. Our case report is the first manuscript to describe diffusion restriction of a cerebral lesion seen in the setting of JXG. Since diffusion restriction has not been described in the setting of JXG but it is more commonly associated with infectious cerebral abscess, this finding has had significant impact in the management. Central nervous system (CNS) lesion of our patient has also had additional imaging features similar to typical infectious cerebral abscess. Extensive work-up has been unrevealing any infectious source. Patient has had biopsy proven peripheral sterile abscesses. After extensive discussion with the family, brain biopsy is deferred. Intravenous steroid therapy is initiated in intensive care setting. All of the lesions have gradually responded to steroid therapy. CNS lesion has taken the longest time to clear.

Distribution and characterization of subtypes of penile intraepithelial neoplasia and their association with invasive carcinomas: a pathological study of 139 lesions in 121 patients.

We are presenting the morphological features of 121 cases of atypical penile intraepithelial lesions. The term penile intraepithelial neoplasia (PeIN) was used to encompass all of them, and lesions were classified into 2 major groups, differentiated and undifferentiated. The latter was further divided in warty, basaloid, and warty-basaloid subtypes. Ninety-five cases were associated with invasive squamous cell carcinomas. Differentiated lesions predominated (68%), followed by warty-basaloid (14%), basaloid (11%), and warty (7%) subtypes. Multifocality was found in 15% of the cases. Differentiated lesions were preferentially located in foreskin, whereas warty and/or basaloid subtypes were more prevalent in the glans. The former lesions were preferentially seen in association with keratinizing variants of squamous carcinoma, whereas the latter subtypes were found mostly in conjunction with invasive warty, basaloid, and warty-basaloid carcinomas. Lichen sclerosus was present in 51% of cases of differentiated lesions and absent in warty and/or basaloid subtypes. In summary, PeIN can be classified into 4 distinctive morphological subtypes. The proper pathological characterization of these lesions may provide important clues to the understanding of the pathogenesis and natural history of penile cancer.

Primary holocord ganglioneuroblastoma: case report.

The authors present a case of extensive primary intramedullary spinal CNS ganglioneuroblastoma (GNB) in a 23-year-old man. Central nervous system GNB is a poorly differentiated neuroepithelial tumor composed of neuroblasts and differentiated ganglion cells, and these lesions are extremely uncommon. Most previously reported primary intraaxial neuroblastic tumors were described in the brain. There has been only one other report of primary spinal cord CNS GNB published to date; the clinical course and prognosis for primary spinal cord tumors of this type are unknown. Similar tumor types demonstrate poor prognoses. This 23-year-old man presented after 9 months of progressive myelopathy. Admission MR imaging showed an intraaxial enhancing mass extending from C-3 to the conus medullaris, with a holocord appearance in several areas. Due to the tumor size, operative intervention was initially limited to biopsy sampling. Chemotherapy resulted in histological maturation, but initial tumor regression was temporary. The patient suffered progressive quadriparesis, and neuroimaging demonstrated slow enlargement of the tumor and an associated syrinx. Nineteen months after diagnosis, the tumor was excised to gross-total resection in a 2-stage operation. One year following resection, the patient had no radiographic recurrence and was functional in a wheelchair with minimal paresis in the upper extremities. This case represents the most extensive example of primary spinal intramedullary CNS GNB reported to date. Holocord tumors present a significant challenge to the neurosurgeon, and resection bears substantial risk of morbidity. In spinal cord CNS GNB, chemotherapy followed by complete resection may be the most effective means of tumor control.

Distinctive immunohistochemical profile of penile intraepithelial lesions: a study of 74 cases.

Several classification schemes for penile precancerous lesions have been proposed, but none of them seems to correlate with the current understanding of penile cancer pathogenesis. Recently, a system, which takes into account morphologic features and purported etiopathogenesis, was proposed, separating penile intraepithelial neoplasia (PeIN) in differentiated and warty/basaloid subtypes. This study was designed to seek an immunohistochemical profile that can be helpful in the classification and differential diagnosis of penile epithelial abnormalities and precancerous lesions using the aforementioned system. The immunohistochemical panel included stains for p16, p53, and Ki-67. For p16 immunostaining, only full-thickness positivity in all epithelial cells was considered as positive; for p53 and Ki-67 immunostaining, patchy or diffuse nuclear positivity above the basal layer was considered as positive. Seventy-four lesions in 59 patients were selected and classified as follows: differentiated PeIN, 34 cases; squamous hyperplasia (SH), 21 cases; basaloid PeIN, 15 cases; and warty PeIN, 4 cases. The mean age of patients was 64 years. Forty-two lesions (56.8%) were located in the glans and 32 (43.2%) in the foreskin. Overexpression of p16 was useful for distinguishing SH from warty/basaloid PeINs (0% vs. 94.7%, P<0.0001) but not SH from differentiated PeINs (0% vs. 5.9%, P=0.519). In addition, p16 allowed the distinction of differentiated and warty/basaloid PeINs (5.9% vs. 94.7%, P<0.0001). Immunohistochemistry results for p53 allowed the separation of SH and differentiated PeIN (9.5% vs. 44.1%, P=0.0078) and SH and warty/basaloid PeIN (9.5% vs. 55.6%, P=0.0042). Ki-67 immunostain was useful for distinguishing SH from differentiated PeIN (52.6% vs. 89.7%, P=0.0062) and SH from PeIN with warty and/or basaloid features (52.6% vs. 100%, P=0.0011). There seems to be a distinctive immunohistochemical profile for associated and precursor epithelial lesions of the penis. SH was p16 and p53 negative, with variable Ki-67 positivity. Differentiated PeIN was p16 negative and Ki-67 positive, with variable p53 positivity. Basaloid and warty PeINs were consistently p16 and Ki-67 positive, with variable p53 positivity. The use of a triple p16/p53/Ki-67 immunohistochemical panel was found to be helpful in the classification, differential diagnosis, and morphologic standardization of penile intraepithelial lesions.