Cytopathological analysis of salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the indications for fine-needle cytology and the modalities of frozen section pathological analysis in the management of salivary gland cancer.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group who drafted a narrative review of the literature published on Medline and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group according to the formal consensus method.

RESULTS

Fine-needle cytology is recommended as part of the diagnostic work-up for a major salivary gland tumor suspicious for malignancy. Fine-needle cytology should be performed after MRI to avoid artifacts. Frozen section analysis is recommended to confirm the malignant nature of the tumor, to adapt the extent of resection and to indicate neck dissection. Whenever possible, the entire tumor and adjacent salivary or periglandular tissue should be sent for frozen section analysis.

CONCLUSION

Fine-needle cytology and frozen section analysis play an essential role in the management of salivary gland cancers.

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.

Guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL), part I: Primary treatment of pleomorphic adenoma

INTRODUCTION

The authors present the guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL) for the diagnosis and treatment of pleomorphic adenoma (PA) of the salivary glands.

METHOD

A review of the literature was performed by a multidisciplinary task force. Guidelines were drafted based on the articles retrieved and the workgroup members' individual experience. Guidelines were graded A, B, C or expert opinion by decreasing level of evidence.

RESULTS

In clinically suspected salivary gland PA, MRI should be performed, including head and neck lymph node levels. Fine needle aspiration cytology is particularly recommended for tumours difficult to characterise by MRI. Frozen section biopsy should be performed to confirm diagnosis and adapt the surgical procedure in case of intraoperative findings of malignancy. Complete resection of the parotid PA should be performed en bloc, including margins, when feasible according to tumour location, while respecting the facial nerve. Enucleation (resection only in contact with the tumour) is not recommended. For the accessory salivary and submandibular glands, complete en bloc resection should be performed.

Guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL), part II: Management of recurrent pleomorphic adenoma of the parotid gland

INTRODUCTION

The authors present the guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL) for the management of recurrent pleomorphic adenoma (RPA) of the parotid gland.

METHOD

A review of the literature was performed by a multidisciplinary task force. Guidelines were drafted, based on the articles retrieved and the work group members' individual experience. There were then read and re-edited by an independent reading group. The proposed recommendations were graded A, B or C on decreasing levels of evidence.

RESULTS

Complete resection under neuromonitoring is recommended in case of RPA. The risks of progression and malignant transformation, which are higher the younger the patient, have to be taken into consideration. The risk of functional sequelae must be explained to the patient. MRI is recommended ahead of any surgery for parotid RPA, to determine extension and detect subclinical lesions. Radiotherapy should be considered in case of multi-recurrent pleomorphic adenoma after macroscopically complete revision surgery at high risk of new recurrence (microscopic residual disease), in case of RPA after incomplete resection, and in non-operable RPA.

Use of fluorescent in-situ hybridisation in salivary gland cytology: A powerful diagnostic tool

OBJECTIVE

Salivary gland cytology is challenging because it includes a diversity of lesions and a wide spectra of tumours. Recently, it has been reported that many types of salivary gland tumours have specific molecular diagnostic signatures that could be identified by fluorescent in-situ hybridisation (FISH). The aim of the present study was to demonstrate the feasibility and efficiency of FISH on routine cytological salivary gland smears.

METHODS

FISH was conducted on 37 cytological salivary gland smears from 34 patients. According to the cytological diagnosis suspected, MECT1/MAML2 gene fusion and rearrangements of PLAG1, MYB, or ETV6 were analysed. The presence and percentages of cells that had gene rearrangements were evaluated. Results were compared with the histological surgical samples, available from 26 patients.

RESULTS

The PLAG1 rearrangement was observed in 12/20 (60%) cases of pleomorphic adenoma. MECT1/MAML2 gene fusion was observed in 1:2 mucoepidermoid carcinomas but was not observed in five other tumours (two pleomorphic adenomas, one Warthin's tumour, one mammary analogue secretory carcinoma [MASC] and one cystic tumour). MYB rearrangement was observed in 4/4 adenoid cystic carcinomas. ETV6-gene splitting identified one MASC.

CONCLUSION

Overall, FISH had a specificity of 100% and a sensitivity of 66.7%. When FISH and cytological analyses were combined, the overall sensitivity was increased to 93.3%. It can thus be concluded that when the FISH analysis is positive, the extent of surgery could be determined with confidence pre-operatively without needing a diagnosis from a frozen section.

Subventricular zones: new key targets for glioblastoma treatment

Background

We aimed to identify subventricular zone (SVZ)-related prognostic factors of survival and patterns of recurrence among patients with glioblastoma.

Methods

Forty-three patients with primary diagnosed glioblastoma treated in our Cancer Center between 2006 and 2010 were identified. All patients received surgical resection, followed by temozolomide-based chemoradiation. Ipsilateral (iSVZ), contralateral (cSVZ) and bilateral (bSVZ) SVZs were retrospectively segmented and radiation dose-volume histograms were generated. Multivariate analysis using the Cox proportional hazards model was assessed to examine the relationship between prognostic factors and time to progression (TTP) or overall survival (OS).

Results

Median age was 59 years (range: 25–85). Median follow-up, OS and TTP were 22.7 months (range 7.5–69.7 months), 22.7 months (95% CI 14.5–26.2 months) and 6.4 months (95% CI 4.4–9.3 months), respectively. On univariate analysis, initial contact to SVZ was a poor prognostic factor for OS (18.7 vs 41.7 months, p = 0.014) and TTP (4.6 vs 12.9 months, p = 0.002). Patients whose bSVZ volume receiving at least 20 Gy (V20Gy) was greater than 84% had a significantly improved TTP (17.7 months vs 5.2 months, p = 0.017). This radiation dose coverage was compatible with an hippocampal sparing. On multivariate analysis, initial contact to SVZ and V20 Gy to bSVZ lesser than 84% remained poor prognostic factors for TTP (HR = 3.07, p = 0.012 and HR = 2.67, p = 0.047, respectively).

Conclusion

Our results suggest that contact to SVZ, as well as insufficient bSVZ radiation dose coverage (V20Gy <84%), might be independent poor prognostic factors for TTP. Therefore, targeting SVZ could be of crucial interest for optimizing glioblastoma treatment.

A case of laryngeal sialolipoma: pathology in focus

We are reporting a rare case of laryngeal sialolipoma in a 66-year-old male affected by Parkinson's disease. He was evaluated for dysarthria and swallowing disorders during which a swelling of the left ventricular fold, was always present and enlarged over a span of six months. Surgical removal of the left ventricular fold was performed. Microscopic examination, showed a circumscribed mass with organoid seromucous glands surrounded by numerous mature adipocytes, separated from the parenchyma and fatty tissue by dense fibrous tissue. This mass fulfilled the diagnostic criteria of sialolipoma. Sialolipomas can develop in a variety of sites in which there is both adipose and salivary gland tissue. To our knowledge, this is the first case of sialolipoma arising in the larynx.

Hepatitis E virus-induced neurological symptoms in a kidney-transplant patient with chronic hepatitis

It has been shown that hepatitis E virus (HEV) may be responsible for chronic hepatitis in solid-organ transplant patients. It has also been suggested that HEV may be responsible for atypical neurological symptoms during the acute phase. However, the relationship between the neurological symptoms and HEV infection was based on the detection of anti-HEV IgM in the sera. Herein, we report a case where neurological symptoms, that is peripheral nerve involvement with proximal muscular weakness that affected the four limbs joints with central nervous-system involvement and bilateral pyramidal syndrome, occurred in a kidney-transplant patient who was chronically infected by HEV. For the first time, HEV RNA was detected in the serum and cerebrospinal fluid. In addition, clonal HEV sequences were analyzed in both compartments, that is serum and cerebrospinal fluid. The discovery of quasispecies compartmentalization and its temporal association suggests that neurological symptoms could be linked to the emergence of neurotropic variants.

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.

Increased exposure to statins in patients developing chronic muscle diseases: a 2-year retrospective study

OBJECTIVE

Case reports have suggested that lipid-lowering drugs (LLDs), especially statins, could induce or reveal chronic muscle diseases. We conducted a study to evaluate the association between chronic muscle diseases and prior exposure to LLDs.

METHOD

This was a retrospective study of chronic primary muscle disease cases newly diagnosed at the Toulouse University Hospitals between January 2003 and December 2004 among patients living in the Midi-Pyrénées area, France. All patients remained symptomatic for more than 1 year after drug withdrawal, or required drugs for inflammatory myopathy. Data on the patient's exposure to LLDs and to other drugs were compared with that of matched controls (5/1) selected through the Midi-Pyrénées Health Insurance System database.

RESULTS

A total of 37 patients were included in the study. Of those, 21 (56.8%) suffered from dermatomyositis (DM) or polymyositis (PM), 12 (32.4%) from genetic myopathy, and 4 (10.8%) from an unclassified disease. The prevalence of exposure to statins was 40.5% in patients and 20% in controls (odds ratio (OR) 2.73, 95% confidence interval (CI) 1.21-6.14; p<0.01). There was a significant positive interaction between statins and proton pump inhibitors exposure (weighted OR 3.3, 95% CI 1.37-7.54; p = 0.02). Statin exposure rate was 47.6% among patients with DM/PM (OR 3.86, 95% CI 1.30-11.57; p<0.01). There was no difference between patients and controls for exposure to fibrates.

CONCLUSION

Patients who developed chronic muscle diseases after the age of 50, including DM/PM, had a higher than expected frequency of prior exposure to statins. Further studies are needed to confirm this association and the role of proton pump inhibitors.

Time course of COX-1 and COX-2 expression during ischemia-reperfusion in rat skeletal muscle

The aim of this study was to assess cyclooxygenase (COX)-1 and COX-2 expression in skeletal muscle after an ischemia-reperfusion (I/R). Male Sprague-Dawley rats were subjected to unilateral hindlimb ischemia for 2 h and then euthanized after 0, 1, 2, 4, 6, 10, 24, and 72 h of reperfusion. The COX protein and mRNA were assessed in control and injured gastrocnemius muscle. Muscle damage was indirectly determined by plasma creatine kinase activity and edema by weighing wet muscle. Creatine kinase activity in plasma increased as early as 1 h after reperfusion and returned to control levels by 72 h of reperfusion. Edema was observed at 6 and 10 h of reperfusion, but histological investigations showed an absence of tissular inflammatory cell infiltration. COX-1 mRNA was expressed in control muscle and was increased at 72 h of reperfusion, but the levels of associated COX-1 protein detected in control and injured gastrocnemius muscle were similar. COX-2 mRNA was not, or only slightly, detectable in control muscle and after I/R. In contrast, I/R induced major overexpression of COX-2 immunoreactivity at 6 and 10 h of reperfusion with a maximum at 10 h, whereas COX-2 protein was undetectable in control muscle. In conclusion, hindlimb I/R induced a large overexpression of COX-2 but not COX-1 protein between 6 and 10 h after injury. These results suggest a role for COX-2 enzyme in such pathophysiological conditions of the skeletal muscle.

Immunodetection of SV40 large T antigen in human central nervous system tumours

BACKGROUND/AIMS

DNA sequences from Simian virus 40 (SV40) have been previously isolated from various human tumours of the central nervous system (CNS). This study aimed to investigate a series of tumours of the CNS for the expression of the SV40 large T antigen (Tag), which is an oncogenic protein of the virus.

METHODS

A French series of 82 CNS tumours was investigated for Tag expression using a monoclonal antibody and immunohistochemistry. A Tag positive hepatocellular carcinoma cell line from transgenic mice and a kidney biopsy from a patient infected by SV40 were used as positive controls.

RESULTS

None of the tumours (20 ependymomas, 20 glioblastomas, 12 oligodendrogliomas, three plexus choroid adenomas, two plexus choroid carcinomas, 15 meningiomas, and 10 medulloblastomas) contained SV40 Tag positive cells.

CONCLUSIONS

The lack of SV40 Tag in 82 CNS tumours of various types is at variance with previous studies from different countries, and suggests that the virus may not be an important factor in CNS tumorigenesis, at least in French cases.

Detection of human cytomegalovirus genome and gene products in central nervous system tumours

Human cytomegalovirus (HCMV) genome and related proteins have been reported in a great proportion of malignant gliomas. However, these results are unexpected since HCMV is not known as an oncogenic virus. By immunohistochemistry (with an anti-IE1 monoclonal antibody) and in situ hybridisation (with biotinylated DNA probes) on tissue microarrays and frozen sections, we investigated a French series of central nervous system (CNS) tumours, including 97 glioblastomas. In 10 cases of glioblastoma, rare astrocyte-like cells, admixed with tumour cells, stained positively for HCMV and in one case a doubtful staining of rare cells was noticed. This may indicate a reactivation of the virus under local immunosuppression but none of the cases of CNS tumours (n=132) contained HCMV genomes and/or proteins in a significant proportion of tumour cells. Our results strongly suggest that HCMV is unlikely to be implicated in the development of human malignant gliomas, at least in French cases.

Intracellular ferritin accumulation in neural and extraneural tissue characterizes a neurodegenerative disease associated with a mutation in the ferritin light polypeptide gene

Abnormal accumulation of ferritin was found to be associated with an autosomal dominant slowly progressing neurodegenerative disease clinically characterized by tremor, cerebellar ataxia, parkinsonism and pyramidal signs, behavioral disturbances, and cognitive decline. These symptoms may appear sequentially over a period of 4 decades. Pathologically, intranuclear and intracytoplasmic bodies were found in glia and subsets of neurons in the central nervous system as well as in extraneural tissue. Biochemical analyses of these bodies isolated from the striatum and cerebellar cortex revealed that ferritin light polypeptide (FTL) and ferritin heavy polypeptide (FTH1) were the main constituents. Molecular genetic studies revealed a 2-bp insertion mutation in exon 4 of the FTL gene. The resulting mutant polypeptide is predicted to have a carboxy terminus that is altered in amino-acid sequence and length. In tissue sections, the bodies were immunolabeled by anti-ferritin and anti-ubiquitin antibodies and were stained by Perls' method for ferric iron. Synthetic peptides homologous to the altered and wild-type carboxy termini were used to raise polyclonal antibodies. These novel antibodies as well as an antibody recognizing FTH1 immunolabeled the bodies. This study of this disorder has provided additional knowledge and insights in the growing area of ferritin-related neurodegeneration.

[Rhino-cerebral fungal infection successfully treated with supplementary hyperbaric oxygen therapy]

Rhino-cerebral fungal infections are rare and difficult disorders to cure. We report the case of a woman presenting a left trigeminal neuralgia complicated by ophthalmoplegia and blindness. MRI demonstrated a lesion of the left orbital apex with extension into the cavernous sinus. Fungal infiltration (aspergillosis or mucormycosis), was seen on biopsy. High-dose liposomal Amphotericin B (5mg/kg/day) for six weeks was unsuccessful. Adjunctant hyperbaric oxygen therapy led to clinical and radiological improvement. Hyperbaric oxygen therapy is discussed in the medical management of rhino-cerebral yeast abscesses.

[Value of interventional video-endoscopy in the assessment of cancer of the upper airways and digestive system]

INTRODUCTION

The aim of our study was to evaluate the video fiberoscope with operator canal (FOC) in he diagnosis of head and neck carcinoma compared to direct laryngoscopy (DL).

METHODOLOGY

From August 2000 to May 2001, 82 patients were included in a prospective study. They were examined for pharyngolaryngeal cancer with the FOC, DL and a CAT-SCAN. The compared elements were the visualization of the different regions of the pharyngolarynx. A three dimensional description of the lesion, the presence of secondary localisations as well as the anatomo pathological results were obtained with FOC and DL.

RESULTS

Although the pharyngolarynx is less well visualized in FOC than in DL (p = 0.04), no statistically significant difference was found between the two methods in terms of visual diagnosis and assessment of the extent of the lesion. The sensitivity of the biopsies made with FOC is lower than those performed with DL (66% FOC, 97% DL). Moreover, we have noted that FOC is highly reliant on the experience and ability of the surgeon.

CONCLUSION

DL remains the most reliable technique for the exploration and diagnosis of the pharyngolarynx. If it is not possible to perform a DL or if it is not indicated (trismus, contra-indication to general anaesthesia) FOC should be considered as the examination of choice.

Value of investigation in the diagnosis of allergic fungal rhinosinusitis: results of a prospective study

The authors report a prospective study in which the aim was to analyse the usefulness of different criteria in optimizing the diagnosis of allergic fungal rhinosinusitis. From 1995 to 1998, 165 patients were operated on for chronic rhinosinusitis. Investigations used in this study for the diagnosis of allergic Aspergillus rhinosinusitis consisted of an analysis of clinical, radiological, immuno-allergic criteria. Fourteen patients presented with allergic Aspergillus rhinosinusitis. One hundred and fifty-one patients did not present any of the necessary criteria for the diagnosis of allergic Aspergillus rhinosinusitis. The results show that the characteristic macroscopic appearance, the maxillary sinus localization, and the presence of positive specific IgE to Aspergillus fumigatus are arguments that reinforce the diagnostic certitude of allergic fungal sinusitis. No specific clinical or radiological criteria orients a diagnosis of chronic rhinosinusitis toward that of allergic fungal rhinosinusitis. The other immuno-allergic tests do not contribute to the diagnosis of allergic fungal rhinosinusitis. pathological, mycological, and

[Neurodegenerative disease associated with a mutation of codon 279 (N279K) in exon 10 of Tau protein]

Frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17) are related to pathogenic mutations of the Tau gene. One of these, located at codon 279, results in an asparagine to lysine substitution. It was detected in three unrelated families from different origins. This mutation affects splicing, allowing exon 10 to be incorporated more frequently in the Tau transcripts, causing an abnormal preponderance of three-over four-repeat isoforms in soluble tau and the presence of the four-repeat isoforms in the insoluble tau. To better understand this newly described pathology, we analysed data from the three previously reported families. The American family, described as "pallido-ponto-nigral degeneration" is a large family which has been extensively studied (13 neuropathological studies). The Japanese family was initially presented as "pallidonigroluysian degeneration with iron deposition" and recently found to be related to N279 K mutation. We reported clinical, pathological and genetic data from the French family. Clinical particularities are ocular movements alterations with vertical supranuclear palsy, extrapyramidal signs (rigidity, dyskinesia, with atypical resting and postural tremor) and progressive dementia. Partial or no L-DOPA responsiveness is noted. These features led to discuss progressive supranuclear palsy, in some cases. There is no amyotrophy, nor any sensibility to neuroleptics, both signs being observed in other FTDP-17 syndromes. Neuropathology and immunohistochemistry confirm the presence of Tau immunolabeled inclusions, affecting mainly neurons in brain stem nuclei and glial cells in supratentorial white matter. Neuronal loss, which is moderate in frontal and temporal cortex, is severe in substantia nigra and globus pallidum. It is variable in other subcortical structures. In these structures, it is associated with iron deposition. This latter may participate in the degenerative process of cells and led to death in some specific neurons. The selectivity of neuronal death in hereditary diseases, when compared to data concerning sporadic neurodegenerative diseases which share similar clinical signs and neuropathological lesions, reinforces the hypothesis of an increased vulnerability of some neuronal populations which express specific sets of tau isoforms. Neurons particularly involved in these diseases express exclusively exon 10 + tau isoforms.

[Anaplastic temporal ganglioglioma with spinal metastasis]

We report the case of a 26-year-old male who was operated on after an acute episode complicating a long history of seizures. The resected temporal lesion was an anaplastic ganglioglioma. Ganglioglioma is a tumor of children and young adults, characterized by two cell components, neuronal and glial. It is usually a benign lesion. The present case is remarkable in several aspects. Hemorrhage led to the discovery of a supra-tentorial tumour. Microscopic examination revealed anaplastic foci in an otherwise typical lesion. There was a long past medical history but outcome was rapidly unfavorable after surgical resection and associated with dissemination along the spinal cord.

Lysosomal sphingomyelinase is not solicited for apoptosis signaling

Stress-induced activation of an acidic sphingomyelinase leading to generation of ceramide, an important lipid mediator, has been associated with apoptosis; however, the implication of this hydrolase has been questioned. The present study aimed at re-evaluating the role of this lysosomal enzyme in apoptosis initiated by different apoptotic inducers. The sensitivity of a series of acid sphingomyelinase-deficient cell lines derived from Niemann-Pick disease patients to stress-induced apoptosis was investigated. We have now shown that stress stimuli, such as anthracyclines, ionizing radiation, and Fas ligation trigger similar apoptotic hallmarks in normal and acid sphingomyelinase-deficient cell lines. Retrovirus-mediated gene correction of enzyme deficiency in Niemann-Pick cells does not modify response to apoptosis. Ceramide production is comparable in normal and Niemann-Pick cells, and increased activity of neutral sphingomyelinase is observed. Thus, our findings cast serious doubts that lysosomal sphingomyelinase activation is responsible for stress-induced apoptosis of cultured cells.

[Lysosomal disorders. Diagnostic role of extra-cerebral biopsy]

Lysosomal disorders are related to dysfunctions of lysosomes which may affect enzymes, transporters or activators. Their clinical features are varied. This is due to several mechanisms, the metabolism of nervous tissue explaining its particular involvement in sphingolipidosis. The classifications are still changing and, recently, some ceroid-lipofuscinosis were included in this group. Biological diagnosis relies on biochemical study of accumulated substrate or on enzymatic assays. It remains sometimes difficult. The analysis of tissue is then a useful tool. Biopsies from extraneural tissues, essentially skin and conjunctival biopsies, are nowadays preferred to brain biopsies. However, the location of the biopsy varies according to the suspected disease. The specimen must be adequately prepared and electron microscopy is necessary. Results of this examination are summarized. The interest of the biopsy is not restricted to diagnosis, it is useful in follow-up of treated patients and for understanding the underlying pathophysiology.

Stress-induced apoptosis is not mediated by endolysosomal ceramide

A major lipid-signaling pathway in mammalian cells implicates the generation of ceramide from the ubiquitous sphingolipid sphingomyelin (SM). Hydrolysis of SM by a sphingomyelinase present in acidic compartments has been reported to mediate, via the production of ceramide, the apoptotic cell death triggered by stress-inducing agents. In the present study, we investigated whether the ceramide formed within or accumulated in lysosomes indeed triggers apoptosis. A series of observations strongly suggests that ceramide involved in stress-induced apoptosis is not endolysosomal: 1) Although short-chain ceramides induced apoptosis, loading cells with natural ceramide through receptor-mediated endocytosis did not result in cell death. 2) Neither TNF-alpha nor anti-CD95 induced the degradation to ceramide of a natural SM that had been first introduced selectively into acidic compartments. 3) Stimulation of SV40-transformed fibroblasts by TNF-alpha or CD40 ligand resulted in apoptosis equally well in cells derived from control individuals and from patients affected with Farber disease, having a genetic defect of acid ceramidase activity leading to lysosomal accumulation of ceramide. Also, induction of apoptosis using anti-CD95 (Fas) or anti-CD40 antibodies, TNF-alpha, daunorubicin, and ionizing radiation was similar in control and Farber disease lymphoid cells. In all cases, apoptosis was preceded by a comparable increase of intracellular ceramide levels. 4) Retroviral-mediated gene transfer and overexpression of acid ceramidase in Farber fibroblasts, which led to complete metabolic correction of the ceramide catabolic defect, did not affect the cell response to TNF-alpha and CD40 ligand.

[Fatal familial insomnia]

Since its description in 1986, Fatal Familial Insomnia (FFI) became the third most common inherited prion diseases (23 described families, 3 isolated cases). It is characterized by a mutation at codon 178 of the prion protein gene cosegregating with the methionine polymorphism at codon 129 of the mutated allele. Insomnia, dysautonomia, disruption of circadian rhythms and motor dysfunctions (myoclonus, ataxia, dysarthria, spasticity) are the main clinical symptoms in the homozygote patients (met/met at codon 129). Heterozygotes have motor dysfunctions from onset and cognitive changes. Pheno-typic variability does not appear to be strictly related to codon 129 polymorphism as recently stressed in some reports. Neuropathology shows marked neuronal loss and gliosis in the thalamus, especially in the medio-dorsal and antero-ventral nuclei, without any amyloïd deposits. Some spongiosis may be seen essentially in the cerebral cortex, in patients with longer duration disease. The D178N mutation coupled with the 129 valine codon is linked to a subtype of Creutzfeldt-Jakob disease. However, in these two phenotypically different diseases, two protease resistant fragments of the pathogenic PrP (PrPres) are accumulated. They differ in molecular mass. In FFI PrPres, the unglycosylated form is underrepresented. This particularity does not result from the preferential conversion of the glycosylated forms but from an inaccessibility of non glycosylated form to conversion. PrPres has been shown to be form allelic origin. Neuronal apoptosis was found to contribute to neuronal loss in FFI. Its presence correlates with neuronal loss, being invariably noticed in the thalamus and medullary nuclei. It is not correlated with PrPres accumulation. The quantity of deposits is globally low in FFI brains and rarely immunohistochemically detected. Pathogenesis of lesions and clinical signs remain to be assessed. Protein dysfunction could be hypothesized according to some clinical and experimental data as well as to the discordance between protein accumulation and programmed cell death. Neurotoxicity is also postulated. Studies on this pathology led to consider the existence of "strains" in human prion diseases. Despite remarkable advances, many issues remain unsolved in this non spongiform prion disease.