Molecular and clinical diversity in primary central nervous system lymphoma.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is a rare and distinct entity within diffuse large B-cell lymphoma presenting with variable response rates probably to underlying molecular heterogeneity. PATIENTS AND METHODS: To identify and characterize PCNSL heterogeneity and facilitate clinical translation, we carried out a comprehensive multi-omic analysis [whole-exome sequencing, RNA sequencing (RNA-seq), methylation sequencing, and clinical features] in a discovery cohort of 147 fresh-frozen (FF) immunocompetent PCNSLs and a validation cohort of formalin-fixed, paraffin-embedded (FFPE) 93 PCNSLs with RNA-seq and clinico-radiological data. RESULTS: Consensus clustering of multi-omic data uncovered concordant classification of four robust, non-overlapping, prognostically significant clusters (CS). The CS1 and CS2 groups presented an immune-cold hypermethylated profile but a distinct clinical behavior. The 'immune-hot' CS4 group, enriched with mutations increasing the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and nuclear factor-κB activity, had the most favorable clinical outcome, while the heterogeneous-immune CS3 group had the worse prognosis probably due to its association with meningeal infiltration and enriched HIST1H1E mutations. CS1 was characterized by high Polycomb repressive complex 2 activity and CDKN2A/B loss leading to higher proliferation activity. Integrated analysis on proposed targets suggests potential use of immune checkpoint inhibitors/JAK1 inhibitors for CS4, cyclin D-Cdk4,6 plus phosphoinositide 3-kinase (PI3K) inhibitors for CS1, lenalidomide/demethylating drugs for CS2, and enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) inhibitors for CS3. We developed an algorithm to identify the PCNSL subtypes using RNA-seq data from either FFPE or FF tissue. CONCLUSIONS: The integration of genome-wide data from multi-omic data revealed four molecular patterns in PCNSL with a distinctive prognostic impact that provides a basis for future clinical stratification and subtype-based targeted interventions.

Characteristics of IDH-mutant gliomas with non-canonical IDH mutation.

BACKGROUND: Approximately 10% of IDH-mutant gliomas harbour non-canonical IDH mutations (non-p.R132H IDH1 and IDH2 mutations). OBJECTIVE: The aim of this study was to analyse the characteristics of non-canonical IDH-mutant gliomas. MATERIALS AND METHODS: We retrospectively analysed the characteristics of 166 patients with non-canonical IDH mutant gliomas and compared them to those of 155 consecutive patients with IDH1 p.R132H mutant gliomas. RESULTS: The median age at diagnosis was 38 years in patients with non-canonical IDH mutant gliomas and 43 years in glioma patients with IDH1 p.R132H-mutant tumours. Family history of cancer was more frequent among glioma patients harbouring non-canonical IDH mutations than in patients with IDH1 p.R132H mutations (22.2% vs 5.1%; P < 0.05). Tumours were predominantly localised in the frontal lobe regardless of the type of IDH mutation. Compared to IDH1 p.R132H-mutant gliomas, tumours with non-canonical IDH mutations were more frequently found in the infratentorial region (5.5% vs 0%; P < 0.05) and were often multicentric (4.8% vs 0.9%; P < 0.05). Compared to IDH1 P.R132H-mutant gliomas, tumours with non-canonical IDH1 mutations were more frequently astrocytomas (65.6% vs 43%, P < 0.05), while those with IDH2 mutations were more frequently oligodendrogliomas (85% vs 48.3%; P < 0.05). The median overall survival was similar in patients with IDH1 p.R132H-mutant gliomas and patients with non-canonical IDH-mutant gliomas. CONCLUSION: Gliomas with non-canonical IDH mutations have distinct radiological and histological characteristics. The presence of such tumours seems to be associated with genetic predisposition to cancer development.

A new prognostic clinicopathological classification of pituitary adenomas: a multicentric case-control study of 410 patients with 8 years post-operative follow-up.

Pituitary adenomas are currently classified by histological, immunocytochemical and numerous ultrastructural characteristics lacking unequivocal prognostic correlations. We investigated the prognostic value of a new clinicopathological classification with grades based on invasion and proliferation. This retrospective multicentric case-control study comprised 410 patients who had surgery for a pituitary tumour with long-term follow-up. Using pituitary magnetic resonance imaging for diagnosis of cavernous or sphenoid sinus invasion, immunocytochemistry, markers of the cell cycle (Ki-67, mitoses) and p53, tumours were classified according to size (micro, macro and giant), type (PRL, GH, FSH/LH, ACTH and TSH) and grade (grade 1a: non-invasive, 1b: non-invasive and proliferative, 2a: invasive, 2b: invasive and proliferative, and 3: metastatic). The association between patient status at 8-year follow-up and age, sex, and classification was evaluated by two multivariate analyses assessing disease- or recurrence/progression-free status. At 8 years after surgery, 195 patients were disease-free (controls) and 215 patients were not (cases). In 125 of the cases the tumours had recurred or progressed. Analyses of disease-free and recurrence/progression-free status revealed the significant prognostic value (p < 0.001; p < 0.05) of age, tumour type, and grade across all tumour types and for each tumour type. Invasive and proliferative tumours (grade 2b) had a poor prognosis with an increased probability of tumour persistence or progression of 25- or 12-fold, respectively, as compared to non-invasive tumours (grade 1a). This new, easy to use clinicopathological classification of pituitary endocrine tumours has demonstrated its prognostic worth by strongly predicting the probability of post-operative complete remission or tumour progression and so could help clinicians choose the best post-operative therapy.

Osteoblastoma of the ethmoid sinus.

Osteoblastoma is a rare benign bone tumor that occurs unusually in the nasal sinuses. We report one case of sinonasal osteoblastoma in a 12-year-old girl who presented with nasal obstruction and telecanthus on the right side. Computed tomography revealed a lesion of the right ethmoid sinus with heterogenous bony density, which was displacing the orbital contents and the skull base. Biopsy caused significant bleeding. Magnetic resonance imaging showed intense homogeneous enhancement with typical flow-void areas due to large pathological vessels. This MRI feature must alert the clinician on the diagnosis before biopsy and surgical resection after embolization is performed. This case report describes the diagnostic and therapeutic difficulties of this rare tumor.

[Chordoma radicular metastasis following cerebrospinal fluid dissemination]. / Métastase radiculaire d'un chordome secondaire à une dissémination dans le liquide cérébrospinal.

INTRODUCTION: Chordoma metastases are usually found at advanced stages of the disease. The metastases occur generally in lung, bones, liver and lymph nodes. We report a rare case of radicular chordoma metastasis. CLINICAL CASE: A 59-year-old man, operated for a clival chordoma six years ago, was admitted for atypical S1 radiculopathy. The MRI showed lumbar intradural tumor compressing the cauda equina. Surgery was performed. RESULTS: After opening of the dura mater, the tumor was seen tightly attached to the nerve roots and was totally removed. The histological examination confirmed a metastasis of the known chordoma without local recurrence. CONCLUSION: Chordomas are slowly growing, aggressive malignancies. Mostly complete microsurgical resection reduces local and distant recurrences. Intradural metastases are rare and follow cerebrospinal fluid dissemination from tumor cells. These metastases must be actively cured to achieve longer survival and better quality of life.

Identification of amino acid residues in the Caenorhabditis elegans POU protein UNC-86 that mediate UNC-86-MEC-3-DNA ternary complex formation.

The POU homeodomain protein UNC-86 and the LIM homeodomain protein MEC-3 are essential for the differentiation of the six mechanoreceptor neurons in the nematode Caenorhabditis elegans. Previous studies have indicated that UNC-86 and MEC-3 bind cooperatively to at least three sites in the mec-3 promoter and synergistically activate transcription. However, the molecular details of the interactions of UNC-86 with MEC-3 and DNA have not been investigated so far. Here we used a yeast system to identify the functional domains in UNC-86 required for transcriptional activation and to characterize the interaction of UNC-86 with MEC-3 in vivo. Our results suggest that transcriptional activation is mediated by the amino terminus of UNC-86, whereas amino acids in the POU domain mediate DNA binding and interaction with MEC-3. By random mutagenesis, we identified mutations that only affect the DNA binding properties of UNC-86, as well as mutations that prevent coactivation by MEC-3. We demonstrated that both the POU-specific domain and the homeodomain of UNC-86, as well as DNA bases adjacent to the proposed UNC-86 binding site, are involved in the formation of a transcriptionally active complex with MEC-3. These data suggest that some residues involved in the contact of UNC-86 with MEC-3 also contribute to the interaction of the functionally nonrelated POU protein Oct-1 with Oca-B, whereas other positions have different roles.

Combining Cadherin Expression with Molecular Markers Discriminates Invasiveness in Growth Hormone and Prolactin Pituitary Adenomas.

Although growth hormone (GH)- and prolactin (PRL)-secreting pituitary adenomas are considered benign, in many patients, tumour growth and/or invasion constitute a particular challenge. In other tumours, progression relies in part on dysfunction of intercellular adhesion mediated by the large family of cadherins. In the present study, we have explored the contribution of cadherins in GH and PRL adenoma pathogenesis, and evaluated whether this class of adherence molecules was related to tumour invasiveness. We have first established, by quantitative polymerase chain reaction and immunohistochemistry, the expression profile of classical cadherins in the normal human pituitary gland. We show that the cadherin repertoire is restricted and cell-type specific. Somatotrophs and lactotrophs express mainly E-cadherin and cadherin 18, whereas N-cadherin is present in the other endocrine cell types. This repertoire undergoes major differential modification in GH and PRL tumours: E-cadherin is significantly reduced in invasive GH adenomas, and this loss is associated with a cytoplasmic relocalisation of cadherin 18 and catenins. In invasive prolactinomas, E-cadherin distribution is altered and is accompanied by a mislocalisation of cadherin 18, ß-catenin and p120 catenin. Strikingly, de novo expression of N-cadherin is present in a subset of adenomas and cells exhibit a mesenchymal phenotype exclusively in invasive tumours. Binary tree analysis, performed by combining the cadherin repertoire with the expression of a subset of known molecular markers, shows that cadherin/catenin complexes play a significant role in discrimination of tumour invasion.

Subcutaneous tumoral seeding from a glioblastoma following stereotactic biopsy: case report and review of the literature.

Extracranial metastases from glioblastoma are uncommon, likely because short patient survival time prevent them to occur. Most of the few previously reported cases occurred after invasive surgical procedures. We describe a case of glioblastoma with concomitant seeding along the stereotactic biopsy trajectory and subcutaneous metastasis. A 60-year-old woman presented with severe headache. Neuroradiological work-up (including cranial computed tomographic scan and magnetic resonance imaging) showed a heterogeneous hyperdensity, suggestive of malignant glioma, in the left parietal region. A computed tomographic-guided stereotactic biopsy was performed and microscopic examination attested a diagnosis of glioblastoma. Radiotherapy and chemotherapy were administered. Eight months later, the patient presented with a subcutaneous tumor in the left occipital region. A cranial computed tomographic scan revealed a large enhancement of the initial tumor, intracranial tumor seeding along the stereotactic biopsy trajectory, and a subcutaneous tumor. Partial resection of the subcutaneous lesion was performed, and histological examination identified an extracranial metastasis from the glioblastoma. Although uncommon, this observation points to the risk of tumor seeding following stereotactic biopsy, and to the close connection between this intracranial seeding and subcutaneous metastasis.

Study of the concordance between p16 immunohistochemistry and HPV-PCR genotyping for the viral diagnosis of oropharyngeal squamous cell carcinoma.

OBJECTIVE: The diagnosis of HPV-related oropharyngeal cancer in clinical practice is based on p16 immunohistochemistry and PCR detection of viral DNA (HPV-PCR). The primary objective of this study was to evaluate the concordance between these 2 diagnostic tests. The secondary objective was to study the clinical characteristics of these patients. MATERIALS AND METHODS: This single-centre prospective study was conducted between February 2010 and July 2012. Immunohistochemical analysis of p16 and HPV-PCR were performed on tumour biopsies. Concordance was evaluated according to Cohen's kappa coefficient and was interpreted according to the Landis and Koch scale. The patients' clinical data were analysed as a function of the diagnostic test results. RESULTS: Seventy-one patients were included in this study. The prevalence of HPV was 43.7% according to p16 and 31% according to HPV-PCR. The concordance study revealed a kappa coefficient of 0.615. A tumour of the tonsil or base of the tongue was detected in 100% of p16+/HPV-PCR+ cases. Smoking and alcohol abuse were significantly less frequent among HPV+ patients regardless of the method of detection. These patients were older and presented tumours with a lower grade of histological differentiation. CONCLUSION: p16 immunohistochemistry or HPV-PCR used alone appear to be insufficient. These results confirm the high prevalence of HPV-related oropharyngeal squamous cell carcinoma (OSCC) and the previously reported specific clinical and histological features, apart from age. It appears essential for future clinical trials to be stratified according to smoking and tumour HPV status, defined by means of reliable virological tests targeting E6/E7 mRNA and no longer a simple positive response to the p16 marker, as is frequently the case at the present time. New tests suitable for use in routine practice therefore need to be developed.

The Caenorhabditis elegans GARP complex contains the conserved Vps51 subunit and is required to maintain lysosomal morphology.

In yeast the Golgi-associated retrograde protein (GARP) complex is required for tethering of endosome-derived transport vesicles to the late Golgi. It consists of four subunits--Vps51p, Vps52p, Vps53p, and Vps54p--and shares similarities with other multimeric tethering complexes, such as the conserved oligomeric Golgi (COG) and the exocyst complex. Here we report the functional characterization of the GARP complex in the nematode Caenorhabditis elegans. Furthermore, we identified the C. elegans Vps51 subunit, which is conserved in all eukaryotes. GARP mutants are viable but show lysosomal defects. We show that GARP subunits bind specific sets of Golgi SNAREs within the yeast two-hybrid system. This suggests that the C. elegans GARP complex also facilitates tethering as well as SNARE complex assembly at the Golgi. The GARP and COG tethering complexes may have overlapping functions for retrograde endosome-to-Golgi retrieval, since loss of both complexes leads to a synthetic lethal phenotype.

Hemangioblastoma of the corpus callosum: A case report and review of the literature on its origin.

A third case of corpus callosum hemangioblastoma (HB) is presented. With no preoperative embolization, surgery was uneventful and the postoperative course was excellent. Based on the literature, we attempted to clarify the histogenesis of HB and to explain why they are exceptional in the supratentorial region in contrast to the posterior cranial fossa. The VHL gene is expressed particularly in Purkinje cells of the cerebellum, but this expression is also possible in supratentorial structures. Its mutation leads to developmental arrest of angioblasts that become potentially neoplastic cells. These CD133-positive pluripotent neoplastic angioblasts, similar to stem cells, may be immature HB in the brain. They also express VEGF, coexpress Epo/EpoR, and are capable of differentiation into primitive vascular structures. This coexpression may not only mediate developmental stagnation, but may also induce HB proliferation. Therefore, HB tumorigenesis may be initiated during embryogenesis and may originate from angiomesenchyma because of the expression of three cell types (stromal cells, pericytes, and endothelial cells) in vimentin. Their capacity for proliferation and differentiation in HB depends on the microenvironment.

[Molecular imaging of tumor hypoxia]. / Imagerie moléculaire de l'hypoxie tumorale.

By allowing an earlier diagnosis and a more exhaustive assessment of extension of the disease, the tomography by emission of positrons (TEP) transforms the care of numerous cancers. At present, (18)F-fluorodesoxyglucose ([(18)F]-FDG) imaging appears as the only one available but new molecular markers are being developed. In the next future they would modify the approach of cancers. In this context, the molecular imaging of the hypoxia and especially the (18)Ffluoromisonidazole TEP ([(18)F]-MISO TEP) can give supplementary information allowing the mapping of hypoxic regions within the tumour. Because of the links, which exist between tumour hypoxia and treatment resistance of very numerous cancers, this information can have an interest, for determination of prognosis as well as for the delineation, volumes to be irradiated. Head and neck tumours are doubtless those for which the literature gives the most elements on the therapeutic impact of tumour hypoxia. Targeted therapies, based on hypoxia, already exist and the contribution of the molecular imaging could be decisive in the evaluation of the impact of such treatment. Molecular imaging of brain tumours remains to be developed. The potential contributions of the [(18)F]-MISO TEP for the care of these patients need to be confirmed. In this context, we propose a review of hypoxia molecular imaging taking as examples head and neck tumours and glioblastomas (GB), two tumours for which hypoxia is one of the key factors to overcome in order to increase therapeutics results.

beta(2)-Microglobulin amyloidosis caused spinal cord compression in a long-term haemodialysis patient.

STUDY DESIGN: A case report of cervical myelopathy caused by epidural beta (2)-microglobulin (beta2m) amyloid deposits in a 50-year-old woman with haemodialysis treatment. OBJECTIVE: Long-term haemodialysis in patients with end-stage renal disease leads to several complications based on beta2m deposits, which can affect, in the cervical spine, the intervertebral disk, and in rare cases, they may compress the spinal cord and nerves. The objective of this report is to describe the clinical and radiological follow-up preceding the indispensable surgical excision of an amyloid mass in a 50-year-old woman with haemodialysis treatment. Long-term postoperative cervicalgia owing to subcondylian bone cyst-associated atlanto-occipital instability is also described and discussed. SETTING: Department of Neurosurgery A, Hop Pellegrin, Bordeaux, France. CASE REPORT: We present a clinical case of a patient with spinal cord compression. The patient was treated by surgical excision of an amyloid mass subsequent to a C2-C3 laminectomy. The patient experienced clinical improvement with a regression of all of her neurological symptoms. Histological findings confirm the diagnosis of beta2m amyloid deposition. However, 5 years after surgery the subcondylian bone cysts were still observed and atlanto-occipital instability required her to wear a minerva. CONCLUSION: Our case report confirms that surgical excision of beta2m epidural deposits is necessary and relevant when neurological prognosis is discussed, and that pain is still the major symptom of disease evolution. The use of high-flux synthetic membranes could decrease the beta2m blood level and early renal graft is the only method to prevent such complications.

Improvement of progressive multifocal leukoencephalopathy after cidofovir therapy in a patient with a destructive polyarthritis.

The human neurotropic JC virus (JCV) is responsible for progressive multifocal leukoencephalopathy (PML), an infectious demyelinating brain disease with major morbidity and mortality, usually refractory to treatment. We describe a PML in a 67-year-old woman with a destructive polyarthritis associated with anti-JO1 antibodies treated with corticosteroids. Although glucocorticoid therapy was maintained, administration of cidofovir improved the neurological condition. Our observation demonstrates the expanding clinical importance of JCV in systemic rheumatic diseases, particularly when immunosuppressive agents are used, and neurological symptoms or white matter changes on central nervous system imaging should arouse the suspicion of PML.

Loss of spr-5 bypasses the requirement for the C.elegans presenilin sel-12 by derepressing hop-1.

Presenilins are part of a protease complex that is responsible for the intramembraneous cleavage of the amyloid precursor protein involved in Alzheimer's disease and of Notch receptors. In Caenorhabditis elegans, mutations in the presenilin sel-12 result in a highly penetrant egg-laying defect. spr-5 was identified as an extragenic suppressor of the sel-12 mutant phenotype. The SPR-5 protein has similarity to the human polyamine oxidase-like protein encoded by KIAA0601 that is part of the HDAC-CoREST co-repressor complex. Suppression of sel-12 by spr-5 requires the activity of HOP-1, the second somatic presenilin in C.elegans. spr-5 mutants derepress hop-1 expression 20- to 30-fold in the early larval stages when hop-1 normally is almost undetectable. SPR-1, a C.elegans homologue of CoREST, physically interacts with SPR-5. Moreover, down-regulation of SPR-1 by mutation or RNA interference also bypasses the need for sel-12. These data strongly suggest that SPR-5 and SPR-1 are part of a CoREST-like co-repressor complex in C.elegans. This complex might be recruited to the hop-1 locus controlling its expression during development.

Presenilin is required for proper morphology and function of neurons in C. elegans.

Mutations in the human presenilin genes cause the most frequent and aggressive forms of familial Alzheimer's disease (FAD). Here we show that in addition to its role in cell fate decisions in non-neuronal tissues, presenilin activity is required in terminally differentiated neurons in vivo. Mutations in the Caenorhabditis elegans presenilin genes sel-12 and hop-1 result in a defect in the temperature memory of the animals. This defect is caused by the loss of presenilin function in two cholinergic interneurons that display neurite morphology defects in presenilin mutants. The morphology and function of the affected neurons in sel-12 mutant animals can be restored by expressing sel-12 only in these cells. The wild-type human presenilin PS1, but not the FAD mutant PS1 A246E, can also rescue these morphological defects. As lin-12 mutant animals display similar morphological and functional defects to presenilin mutants, we suggest that presenilins mediate their activity in postmitotic neurons by facilitating Notch signalling. These data indicate cell-autonomous and evolutionarily conserved control of neural morphology and function by presenilins.

A loss of function mutant of the presenilin homologue SEL-12 undergoes aberrant endoproteolysis in Caenorhabditis elegans and increases abeta 42 generation in human cells.

The familial Alzheimer's disease-associated presenilins (PSs) occur as a dimeric complex of proteolytically generated fragments, which functionally supports endoproteolysis of Notch and the beta-amyloid precursor protein (betaAPP). A homologous gene, sel-12, has been identified in Caenorhabditis elegans. We now demonstrate that wild-type (wt) SEL-12 undergoes endoproteolytic cleavage in C. elegans similar to the PSs in human tissue. In contrast, SEL-12 C60S protein expressed from the sel-12(ar131) allele is miscleaved in C. elegans, resulting in a larger mutant N-terminal fragment. Neither SEL-12 wt nor C60S undergo endoproteolytic processing upon expression in human cells, suggesting that SEL-12 is cleaved by a C. elegans-specific endoproteolytic activity. The loss of function of sel-12 in C. elegans is not associated with a dominant negative activity in human cells, because SEL-12 C60S and the corresponding PS1 C92S mutation do not interfere with Notch1 cleavage. Moreover, both mutant variants increase the aberrant production of the highly amyloidogenic 42-amino acid version of amyloid beta-peptide similar to familial Alzheimer's disease-associated human PS mutants. Our data therefore demonstrate that the C60S mutation in SEL-12 is associated with aberrant endoproteolysis and a loss of function in C. elegans, whereas a gain of misfunction is observed upon expression in human cells.