Real-world EGFR testing practices for non-small-cell lung cancer by thoracic pathology laboratories across Europe

BACKGROUND

Testing for epidermal growth factor receptor (EGFR) mutations is an essential recommendation in guidelines for metastatic non-squamous non-small-cell lung cancer, and is considered mandatory in European countries. However, in practice, challenges are often faced when carrying out routine biomarker testing, including access to testing, inadequate tissue samples and long turnaround times (TATs).

MATERIALS AND METHODS

To evaluate the real-world EGFR testing practices of European pathology laboratories, an online survey was set up and validated by the Pulmonary Pathology Working Group of the European Society of Pathology and distributed to 64 expert testing laboratories. The retrospective survey focussed on laboratory organisation and daily EGFR testing practice of pathologists and molecular biologists between 2018 and 2021.

RESULTS

TATs varied greatly both between and within countries. These discrepancies may be partly due to reflex testing practices, as 20.8% of laboratories carried out EGFR testing only at the request of the clinician. Many laboratories across Europe still favour single-test sequencing as a primary method of EGFR mutation identification; 32.7% indicated that they only used targeted techniques and 45.1% used single-gene testing followed by next-generation sequencing (NGS), depending on the case. Reported testing rates were consistent over time with no significant decrease in the number of EGFR tests carried out in 2020, despite the increased pressure faced by testing facilities during the COVID-19 pandemic. ISO 15189 accreditation was reported by 42.0% of molecular biology laboratories for single-test sequencing, and by 42.3% for NGS. 92.5% of laboratories indicated they regularly participate in an external quality assessment scheme.

CONCLUSIONS

These results highlight the strong heterogeneity of EGFR testing that still occurs within thoracic pathology and molecular biology laboratories across Europe. Even among expert testing facilities there is variability in testing capabilities, TAT, reflex testing practice and laboratory accreditation, stressing the need to harmonise reimbursement technologies and decision-making algorithms in Europe.

Clinical and molecular practice of European thoracic pathology laboratories during the COVID-19 pandemic. The past and the near future

Background

This study evaluated the consequences in Europe of the COVID-19 outbreak on pathology laboratories orientated toward the diagnosis of thoracic diseases.

Materials and methods

A survey was sent to 71 pathology laboratories from 21 European countries. The questionnaire requested information concerning the organization of biosafety, the clinical and molecular pathology, the biobanking, the workload, the associated research into COVID-19, and the organization of education and training during the COVID-19 crisis, from 15 March to 31 May 2020, compared with the same period in 2019.

Results

Questionnaires were returned from 53/71 (75%) laboratories from 18 European countries. The biosafety procedures were heterogeneous. The workload in clinical and molecular pathology decreased dramatically by 31% (range, 3%-55%) and 26% (range, 7%-62%), respectively. According to the professional category, between 28% and 41% of the staff members were not present in the laboratories but did teleworking. A total of 70% of the laboratories developed virtual meetings for the training of residents and junior pathologists. During the period of study, none of the staff members with confirmed COVID-19 became infected as a result of handling samples.

Conclusions

The COVID-19 pandemic has had a strong impact on most of the European pathology laboratories included in this study. Urgent implementation of several changes to the organization of most of these laboratories, notably to better harmonize biosafety procedures, was noted at the onset of the pandemic and maintained in the event of a new wave of infection occurring in Europe.

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Biosafety measures used in the first wave of the COVID-19 crisis were heterogeneous in 53 European pathology laboratories.

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A dramatic decrease of the workload in pathology laboratories was noted.

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No case of healthcare workers contaminated with SARS-CoV-2 associated with samples handling was identified.

The Differential Expression of Galectin-1 and Galectin-3 in Normal Lymphoid Tissue and Non-Hodgkin's and Hodgkin's Lymphomas

The WHO classification of lymphomas was established on the basis of clinical, morphological, immunohistochemical and genetic criteria. However, each entity displays its own spectrum of clinical aggressiveness. Treatment success varies widely and is not predictable. Since galectins are involved in oncogenesis and the physiology of immune cells, we investigated whether galectin-1 and galectin-3 immunohistochemical expression could differ in 25 normal lymphoid tissues, 42 non-Hodgkin's and 14 Hodgkin's lymphomas. Immunohistochemical galectin expression was submitted to semi-quantitative and quantitative (computer-assisted microscopy) evaluations. This study is completed by an analysis (by means of quantitative RT-PCR) of galectin-3 mRNA expression in 3 normal lymph nodes, 3 follicular lymphomas (FLs) and 3 diffuse large B-cell lymphomas (DLBCLs). The data show that in normal lymphoid tissue, lymphocytes do not express galectin-1 and rarely express galectin-3. In contrast, galectin-3 was expressed in 8 of the 16 DLBCL cases and in 1 of the 8 FL cases. Furthermore, galectin-3 mRNA was expressed 3-times more in the DLBCLs than in the FLs. While the blood vessel walls of the lymphomas expressed galectin-1, the vessel walls of normal lymphoid tissues did not. This expression of galectin-1 in blood vessel walls was correlated with vascular density. The present study thus shows that DLBCL can be distinguished from normal lymphoid tissue and other lymphomas on the basis of galectin-3 expression.

[Next generation sequencing]

Fine needle aspiration is the gold standard method to differentiate benign thyroid nodules from malignant. However, for 15 to 30% of the cases the cytological diagnosis is indeterminate, leading to surgery. Integration of new molecular markers is opening new perspectives in order to increase the diagnostic precision of thyroid nodules with an indeterminate cytology.

[How molecular biology can improve the clinical diagnosis of gliomas?]

Gliomas are the most common primary brain tumors and include different diagnoses associated with a different prognosis. Histology remains the gold standard for the diagnosis of these tumors. However, pathologists may encounter diagnostic difficulties due to tumor heterogeneity or to the small size of the samples. Recently, major advances in discovery of molecular alterations of these cancers have led to the development of new molecular markers, some with a diagnostic role, others with a prognostic impact and / or predictive of therapeutic response. The testing of different molecular alterations such as 1p / 19q codeletion, mutations of IDH genes, p16 deletion, EGFR amplification or MGMT promoter methylation has been included in the daily practice in order to confirm the diagnosis, assess the patient prognosis and guide treatment choices.

IGF-IR: a new prognostic biomarker for human glioblastoma

Background:

Glioblastomas (GBMs) are the most common malignant primary brain tumours in adults and are refractory to conventional therapy, including surgical resection, radiotherapy and chemotherapy. The insulin-like growth factor (IGF) system is a complex network that includes ligands (IGFI and IGFII), receptors (IGF-IR and IGF-IIR) and high-affinity binding proteins (IGFBP-1 to IGFBP-6). Many studies have reported a role for the IGF system in the regulation of tumour cell biology. However, the role of this system remains unclear in GBMs.

Methods:

We investigate the prognostic value of both the IGF ligands' and receptors' expression in a cohort of human GBMs. Tissue microarray and image analysis were conducted to quantitatively analyse the immunohistochemical expression of these proteins in 218 human GBMs.

Results:

Both IGF-IR and IGF-IIR were overexpressed in GBMs compared with normal brain (P<10⁻⁴ and P=0.002, respectively). Moreover, with regard to standard clinical factors, IGF-IR positivity was identified as an independent prognostic factor associated with shorter survival (P=0.016) and was associated with a less favourable response to temozolomide.

Conclusions:

This study suggests that IGF-IR could be an interesting target for GBM therapy.

Image cytometry characterization of ploidy level, proliferative activity and chromatin pattern in 50 nasal polyps

A computer-assisted microscope analysis of Feulgen-stained nuclei was carried out on a series of 50 nasal polyps in order to try to identify specific biological subgroups. The present series of 50 nasal polyps includes single polyps both associated (n=9) and unassociated (n=9) with allergy and diffuse polyposis both associated (n=7) and unassociated (n=9) with allergy, cystic fibrosis (n=9) and ASA (aspirin-sinusitis-asthma) related polyposis (n=7). The computer-assisted microscope analysis provides 36 quantitative variables which include 1 variable describing proliferative activity, 9 describing the nuclear desoxyribonucleic acid distribution (DNA ploidy level) and 26 describing nucleus morphology, i.e. its size and chromatin pattern. The results show that the methodology proposed here enabled four major groups of nasal polyps to be identified, i.e. diffuse polyposis associated with allergy, cystic fibrosis-related polyposis, single polyps both associated and unassociated either with allergy and a fourth group including diffuse polyposis not associated with allergy and ASA-related polyposis. These four groups of nasal polyps differed markedly in their morphonuclear characteristics, but not in the proliferative activity- and DNA ploidy-related variables.

Epithelial expression of FHL2 is negatively associated with metastasis-free and overall survival in colorectal cancer

Background:

Four-and-a-half LIM domains protein 2 (FHL2) is a component of the focal adhesion structures and has been suggested to have a role in cancer progression. It has been shown to be overexpressed in the colorectal cancer (CRC).

Methods:

Here, we examined a possible prognostic value of FHL2 in CRC. Immunohistochemistry for FHL2 was performed on 296 CRCs without distant metastases at the time of surgery. Staining in the epithelial compartment was quantitatively evaluated using image analysis, and results were related to clinical variables. Antibody specificity was tested using small-interfering RNA transfection in hTERT-immortalised myofibroblasts.

Results:

Varying degrees of cytoplasmic FHL2 expression by neoplastic epithelial cells were detectable in all cases. Higher FHL2 expression in the epithelial compartment was an independent adverse prognostic factor. Multivariate Cox analysis shows that expression in the tumour invasion front (P<0.001) as well as in the centre of the tumour (P<0.001) was associated with metachronous metastases independently of the clinicopathological variables; expression in the tumour invasion front was also associated with overall survival independently of the clinicopathological variables (P<0.01).

Conclusion:

Higher FHL2 expression is involved in CRC progression and correlates with the development of metachronous metastases and overall survival, suggesting that FHL2 is an independent adverse prognostic indicator for CRC.

The characterization of nuclear-DNA content, the proliferative activity and the immunohistochemical expression of gfap, vim, leu-7, s-100, p53 and cathepsin-d in human glioblastoma multiformes (hgbms) versus human gbm cell-lines grafted into the brains of nude-mice

Experimental models relating to human glioblastoma multiformes (hGBMs) involve the intracranial or intracerebral injection of human GBM cells into nude mice or rats. The aim of the present study was to compare a number of biological characteristics of hGBMs as opposed to experimental GBMs obtained by grafting either human U87 or U373 glioblastoma cells into the brains of nude mice. Biological assessments involve four distinct sets of parameters, i.e. i) the determination of the nuclear DNA content, ii) the determination of proliferative activity, iii) the assessment of p53 nuclear phosphoprotein immunohistochemical reactivity, and iv) the assessment of GFAP, VIM, LEU-7, S-100 and CAT D protein immunohistochemical reactivity. While most of the human glioblastoma multiformes (hGBMs) under study were immunohistochemically reactive to GFAP, S-100, LEU-7 and VIM as indeed were the experimental U373 GBMs, the U87 ones were reactive to VIM only. Furthermore, the U87 GBMs appeared to be more aggressive than the U373 ones since the former were associated with a shorter tumor-bearing mouse survival time than the latter. Such aggressiveness was further associated with a proliferative activity and a cathepsin D immunoreactivity, both of which were markedly higher in the U87 GBMs than in the U373 GBMs. These two experimental GBM models also exhibited tumors which were predominantly diploid. The present study shows that it is possible to set up experimentally in vivo models which strongly mimic human glioblastoma multiformes. Such models consist of grafting human glioblastoma cell lines, namely U87 and U373, into the brains of nude mice. However, while it is true that experimental GBMs closely resemble the hGBMs with respect to some biological characteristics, they also differ in many other significant biological characteristics.

Contribution of CXCR4 and SMAD4 in predicting disease progression pattern and benefit from adjuvant chemotherapy in resected pancreatic adenocarcinoma

BACKGROUND

Prognosis of patients with pancreatic adenocarcinoma is poor. Many prognostic biomarkers have been tested, but most studies included heterogeneous patients. We aimed to investigate the prognostic and/or predictive values of four relevant biomarkers in a multicentric cohort of patients.

PATIENTS AND METHODS

A total of 471 patients who had resected pancreatic adenocarcinoma were included. Using tissue microarray, we assessed the relationship of biomarker expressions with the overall survival: Smad4, type II TGF-β receptor, CXCR4, and LKB1.

RESULTS

High CXCR4 expression was found to be the only independent negative prognostic biomarker [hazard ratio (HR) = 1.74; P < 0.0001]. In addition, it was significantly associated with a distant relapse pattern (HR = 2.19; P < 0.0001) and was the strongest prognostic factor compared with clinicopathological factors. In patients who did not received adjuvant treatment, there was a trend toward decrease in the overall survival for negative Smad4 expression. Loss of Smad4 expression was not correlated with recurrence pattern but was shown to be predictive for adjuvant chemotherapy (CT) benefit (HR = 0.59; P = 0.002).

CONCLUSIONS

CXCR4 is a strong independent prognostic biomarker associated with distant metastatic recurrence and appears as an attractive target to be evaluated in pancreatic adenocarcinoma. Negative SMAD4 expression should be considered as a potential predictor of adjuvant CT benefit.

Expression of endoplasmic reticulum stress markers in the islets of patients with type 1 diabetes

AIMS/HYPOTHESIS

Endoplasmic reticulum (ER) stress may play a role in cytokine-mediated beta cell death in type 1 diabetes, but it remains controversial whether ER stress markers are present in islets from type 1 diabetic individuals. Therefore, we evaluated by immunostaining the expression of markers of the three main branches of the ER stress response in islets from 13 individuals with and 15 controls without type 1 diabetes (eight adults and seven children).

METHODS

Antibodies against the ER stress markers C/EBP homologous protein (CHOP), immunoglobulin heavy chain (BIP) and X-box binding protein 1 (XBP-1) were validated using HeLa cells treated with the ER stressor thapsigargin. These antibodies were then used to stain serial sections of paraffin-embedded pancreas from type 1 diabetic and non-diabetic individuals; samples were also immunostained for CD45, insulin and glucagon. Immunostaining intensities of the ER stress markers were quantified using a software-based, unbiased quantitative approach.

RESULTS

Islets from individuals with type 1 diabetes showed increased levels of CHOP and, at least for insulitis-positive and beta cell-containing islets, BIP. XBP-1 expression was not, however, increased.

CONCLUSIONS/INTERPRETATION

Islet cells from individuals with type 1 diabetes display a partial ER stress response, with evidence of the induction of some, but not all, components of the unfolded protein response.

Molecular changes in pancreatic cancer: implications for molecular targeting therapy

Pancreatic ductal adenocarcinoma has a high mortality rate, which is generally related to the initial diagnosis coming at late stage disease combined with a lack of effective treatment options. Gemcitabine has been the most commonly used drug over the past decade and is still the cornerstone of therapy in adjuvant and metastatic settings. Intrinsic or acquired resistance of tumours to gemcitabine is, however, a major clinical problem. New therapeutic strategies are urgently needed whereas we also need to identify new prognostic and predictive biomarkers. This article focuses on gemcitabine resistance, on the role of chemokines and chemokine receptors in pancreatic carcinoma initiation and progression, and on stellate cells as partners in crime with neoplastic epithelial cells.

Primary bilateral pontine demyelination in a cat with similarity to central pontine myelinolysis

An adult cat was presented with the history of 3 months' weight loss and more recent loss of balance and ataxia. An abdominal mass was palpable; results of neurologic examination suggested a brainstem disorder. The owners elected euthanasia. Postmortem findings included suppurative jejunal lymphadenitis and bilateral demyelination in the ventral pons with sparing of axons and neuronal soma. The location and character of the lesion mimicked those of human central pontine myelinolysis, an iatrogenic condition that may follow rapid correction of hyponatremia or develop spontaneously in patients with malnutrition or energy deprivation. In this cat, the poor nutritional state may have contributed to the development of this novel pontine lesion.

A genomic-based approach identifies FXYD domain containing ion transport regulator 2 (FXYD2)gammaa as a pancreatic beta cell-specific biomarker

AIMS/HYPOTHESIS

Non-invasive imaging of the pancreatic beta cell mass (BCM) requires the identification of novel and specific beta cell biomarkers. We have developed a systems biology approach to the identification of promising beta cell markers.

METHODS

We followed a functional genomics strategy based on massive parallel signal sequencing (MPSS) and microarray data obtained in human islets, purified primary rat beta cells, non-beta cells and INS-1E cells to identify promising beta cell markers. Candidate biomarkers were validated and screened using established human and macaque (Macacus cynomolgus) tissue microarrays.

RESULTS

After a series of filtering steps, 12 beta cell-specific membrane proteins were identified. For four of the proteins we selected or produced antibodies targeting specifically the human proteins and their splice variants; all four candidates were confirmed as islet-specific in human pancreas. Two splice variants of FXYD domain containing ion transport regulator 2 (FXYD2), a regulating subunit of the Na(+)-K(+)-ATPase, were identified as preferentially present in human pancreatic islets. The presence of FXYD2gammaa was restricted to pancreatic islets and selectively detected in pancreatic beta cells. Analysis of human fetal pancreas samples showed the presence of FXYD2gammaa at an early stage (15 weeks). Histological examination of pancreatic sections from individuals with type 1 diabetes or sections from pancreases of streptozotocin-treated Macacus cynomolgus monkeys indicated a close correlation between loss of FXYD2gammaa and loss of insulin-positive cells.

CONCLUSIONS/INTERPRETATION

We propose human FXYD2gammaa as a novel beta cell-specific biomarker.

Glucose-limited chemostat culture of Chinese hamster ovary cells producing recombinant human interferon-gamma

A Chinese hamster ovary (CHO) cell line expressing recombinant human interferon-gamma (IFN-gamma) was grown under glucose limitation in a chemostate at a constant dilution rate of 0.015 h(-1) with glucose feed concentrations of 2.75 mM and 4.25 mM. The changes in cell concentration that accompanied changes in the glucose feed concentration indicated that the cells were glucose-limited. The cell yield on glucose remained constant, but there was a decline in residual glucose concentration and a reduced lactate yield from glucose in the latter stages of the culture. The consumption rates for many of the essential amino acids were increased later in the culture. The volumetric rate of interferon-gamma production was maintained throughout the course of this culture, indicating that IFN-gamma expression was stable under these conditions. However, the specific rate of IFN-gamma production was significantly lower at the higher glucose feed concentration. Under glucose limitation, the proportion of fully glycosylated IFN-gamma produced by these cells was less than that produced in the early stages of batch cultures. The proportion of fully glycosylated IFN-gamma increased during transient periods of glucose excess, suggesting that the culture environment influences the glycosylation of IFN-gamma.

[A case of von Hippel-Lindau disease diagnosed at the autopsy]

A 46-year-old woman presents with walk instability. A diagnosis of cerebellar hemangioblastoma is made on MRI and neurosurgical excision was performed. In the postoperative course, the patient died of a bulbar cerebral stroke with respiratory distress. At the autopsy, the finding of a bilateral renal clear cell carcinoma in addition to the cerebellar hemangioblastoma allows for the diagnosis of von Hippel-Lindau disease. It is an inherited, autosomal dominant syndrome charaterized by a VHL gene mutation. Affected individuals are at risk of developing various benign and malignant tumors of multiple organs, reviewed in this article. Despite a decrease of number of necropsy, this case as the review of literature demonstrates clinical importance of autopsy.

Correlation of CXCR4 expression in resected pancreatic adenocarcinoma (PA) with relapse and survival after adjuvant radiochemotherapy (RCT)

e22022

Background: The chemoreceptors CXCR4, CXCR7 and the hypoxia inductible factor-1 alpha (HIF-1α) are implicated in PA growth, dissemination and angiogenesis. These protagonists are expected to play a key role in radiotherapy and chemotherapy resistance in PA. Methods: We conducted a retrospective study of patients undergoing curative surgery (R0 resection) for PA between 2001 and 2006 in our institution. All were treated with adjuvant RCT (treatment group). The treatment group was case-matched with resected PA patients who did not receive any adjuvant therapy (control group). FFPE specimens were subjected to immunohistochemical analysis using tissue microarray and monoclonal antibodies against human CXCR4, CXCR7, and HIF-1α. Based on the intensity (I) and the extend (E) of staining, cases were stratified into those with high (E x I>3) or low (E x I ≤ 3) expression of CXCR4, CXCR7 and HIF-1α and results were correlated with disease-free survival (DFS) and overall survival (OS). Results: 31 PA patients (median age: 57years, range: 39–76) were analysed in the treatment group and 30 (median age: 59 years, range: 38–81) in the control group. The two groups were well-matched in terms of age, sex, tumor stage (T1-T2 vs T3-T4), tumor differentiation (poor vs well-moderate), lymph node (LN) status (N0 vs N+), lymphatic and vascular embols. In univariate analysis, CXCR4 expression and LN status were associated with DFS and OS (OS, CXCR4low/high: HR, 5.43, 95%CI: 2.03–14.49, p=0.001; N0/N+: HR: 4.62, 95% CI, 1.33–13.12, p=0.016; DFS: CXCR4low/ CXCR4high : HR, 3.01, 95%CI: 1.21–7.46, p=0.018; N0/N+: HR: 3.30, 95% CI, 1.09–9.90, p=0.034) in the treatment group while in the control group LN status was the only variable significantly correlated with DFS and OS. CXCR4 appeared to be the only independant predictor for DFS (CXCR4low/high: HR, 4.95, 95%CI: 1.68–14.71, p=0.007) and OS (CXCR4low/high: HR, 4.76, 95%CI: 2.03–14.49, p=0.004) in the treatment group but not in the control group. Conclusions: CXCR4 was an independant predictor for DFS and OS after adjuvant RCT in resected PA patients. This chemoreceptor could be implicated in the resistance of pancreatic cancer cells to RCT and its targeted inhibition deserves clinical evaluation.

No significant financial relationships to disclose.

The galectin family and digestive disease

The soluble-type lectins or galectins constitute a family of proteins defined by shared consensus amino acid sequence and affinity for beta-galactose-containing oligosaccharides. These molecules are widely distributed in the animal kingdom; to date, 15 mammalian galectins have been described but more are likely to be discovered. These proteins are involved in many biological processes including cell-cell and cell-matrix adhesion, growth regulation, signaling, and cytokine secretion. Over the last decade, a vast amount of reports has shown the importance of several galectins in the development and progression of malignancies in the digestive tract, mainly colorectal cancers. More recent data indicate that some of these molecules are also involved in inflammatory bowel diseases. This review focuses on the current knowledge of galectin expression and putative functions in the oesophagus, stomach, small intestine, and colon. It also highlights that the rapid accumulation of research data promises future scenarios in which individual members of the galectin family and/or their ligands will be used as diagnostic and therapeutic modalities for neoplastic as well as inflammatory disorders. However, the concretization of these potential modalities requires substantial improvements in terms of standardization of galectin expression evaluation together with prospective validation of the present data.

Apparent diffusion coefficient and cerebral blood volume in brain gliomas: relation to tumor cell density and tumor microvessel density based on stereotactic biopsies

BACKGROUND AND PURPOSE

MR imaging-based apparent diffusion coefficient (ADC) and regional cerebral blood volume (rCBV) measurements have been related respectively to both cell and microvessel density in brain tumors. However, because of the high degree of heterogeneity in gliomas, a direct correlation between these MR imaging-based measurements and histopathologic features is required. The purpose of this study was to correlate regionally ADC and rCBV values with both cell and microvessel density in gliomas, by using coregistered MR imaging and stereotactic biopsies.

MATERIALS AND METHODS

Eighteen patients (9 men, 9 women; age range, 19-78 years) with gliomas underwent diffusion-weighted and dynamic susceptibility contrast-enhanced MR imaging before biopsy. Eighty-one biopsy samples were obtained and categorized as peritumoral, infiltrated tissue, or bulk tumor, with quantification of cell and microvessel density. ADC and rCBV values were measured at biopsy sites and were normalized to contralateral white matter on corresponding maps coregistered with a 3D MR imaging dataset. ADC and rCBV ratios were compared with quantitative histologic features by using the Spearman correlation test.

RESULTS

The highest correlations were found within bulk tumor samples between rCBV and cell density (r=0.57, P < .001) and rCBV and microvessel density (r=0.46, P < .01). An inverse correlation was found between ADC and microvessel density within bulk tumor (r=-0.36, P < .05), whereas no significant correlation was found between ADC and cell density.

CONCLUSION

rCBV regionally correlates with both cell and microvessel density within gliomas, whereas no regional correlation was found between ADC and cell density.

Stereotactic comparison among cerebral blood volume, methionine uptake, and histopathology in brain glioma

BACKGROUND AND PURPOSE

Vascularity, metabolism, and histologic grade are related in gliomas but the exact determinants of these relationships are not fully defined. We used image coregistration and stereotactic biopsies to regionally compare cerebral blood volume (CBV) and (11)C-methionine (MET) uptake measurements in brain gliomas and to assess their relationship by histopathologic examination.

MATERIALS AND METHODS

Fourteen patients with brain gliomas underwent MR imaging, including dynamic susceptibility contrast-enhanced MR and positron-emission tomography (PET) using MET acquired in identical stereotactic conditions before biopsy. MR-based CBV maps were calculated and both CBV maps and PET images were coregistered to anatomic images. Sixty-five biopsy samples were obtained on trajectories targeted toward high MET uptake area. The following histopathologic features were semiquantified in each sample: mitotic activity, endothelial proliferation, cellular pleomorphism, and tumor necrosis. CBV and MET uptake values were measured in the biopsy area and normalized to contralateral white matter. CBV ratios were compared with MET uptake ratios, and both measurements were compared with histologic features of each sample.

RESULTS

CBV ratios ranged from 0.08 to 10.24 (median = 1.73), and MET uptake ratios ranged from 0.30 to 4.91 (median = 1.67). There was a positive correlation between CBV ratios and MET uptake ratios (r = 0.65, P < .001). Both CBV and MET uptake ratios were found to be significantly related to endothelial proliferation and mitotic activity (P < .01).

CONCLUSION

Within glial tumors, there is a local relationship between CBV and MET uptake measurements. Both provide indices of focal malignant activity.

Cystic extramedullary ependymoma

Intradural extramedullary location of ependymoma is rare. To the best of our knowledge, only 9 cases have been described in the literature. We report a case of a histologically confirmed ependymoma (WHO grade II) presented in the MR imaging as a cystic, nonenhancing thoracic intradural extramedullary lesion compressing the spinal cord. The cystic appearance mimicking an arachnoid cyst at diagnosis and the leptomeningeal dissemination developed later were peculiarities that have never been previously described in relation to these rare tumors.

Tailgut cyst associated with a carcinoid tumor: case report and review of the literature

We report the case of a 49-year-old woman who presented a tailgut cyst lined by a variety of epithelium including squamous, columnar and transitional. Fortuitously a microscopic carcinoid tumor expressing immunohistochemically neuroendocrine markers was identified in the cystic wall. Tailgut cysts are congenital abnormalities located in the presacrococcygeal area occurring usually in adult patients. Clinical diagnosis is difficult because they are often asymptomatic. Patients may present symptoms resulting from local mass effects or complications. The differential diagnoses include rectal duplication cysts, cystic sacrococcygeal teratomas, epidermal cysts, epidermoid cysts, anal duct or gland cysts. Magnetic resonance imaging has recently become the modality of choice to image the cyst. Malignant transformation is rare; 23 cases including 10 carcinoid tumors have been reported in the literature. To our knowledge, this is the eleventh case of carcinoid tumor arising in a tailgut cyst.

Human galectin-2: expression profiling by RT-PCR/immunohistochemistry and its introduction as a histochemical tool for ligand localization

Sugar-encoded information of glyco-conjugates is translated into cellular responses by endogenous lectins. Galectins stand out against other lectin families due to their wide range of functions including cell adhesion, tissue invasion or growth regulation exerted at extracellular, membrane, cytoplasmic and nuclear sites. This remarkable versatility warrants close scrutiny of their emerging network, in this study with focus on homodimeric human galectin-2. We first detected presence of specific mRNA in various tissue types by processing post mortem and surgical specimens by RT-PCR protocols. Overlap of gene expression was noted with proto-type galectins-1 and -7 and also family members from the other two subgroups. To monitor expression on the level of protein a polyclonal anti-galectin-2 antibody was raised. Immunopositivity was semi-quantitatively assessed in sections of 209 human samples establishing an array both of normal tissues and samples with inflammation or benign/malignant growth. In general, positivity was predominantly epithelial without restriction of staining to certain tissue types, as fittingly indicated by our RT-PCR analysis. Staining was not limited to the cytoplasm but also included nuclear sites. To examine the suitability of the labeled lectin as a histochemical probe we biotinylated galectin-2 under activity-preserving conditions and introduced it to tissue profiling. Specific cytoplasmic staining proved the validity of the concept. Our results encourage systematic histopathologic studies by immuno- and lectin histochemistry, especially by adding galectin-2 as study object to galectin fingerprinting which has already yielded prognostic information on galectins-1, -3, -4 and -8 and hereby contributed to define functional overlap/divergence in this lectin family.

Dark-cell areas in the dog vestibular endorgans: an immunohistochemical study

The stria vascularis in the cochlea and the dark-cell areas in the vestibular endorgans are structures involved in the production of endolymphatic fluid. This study investigated the dark-cell areas in the vestibular endorgans of the dog by classical staining and by immunohistochemistry (anti-Na,K-ATPase beta2 isoform, anti-cytokeratins (against cytokeratins 5 and 8), anti-vimentin and anti-S100A6) from birth to 110 postnatal days. Using classical staining, it was not possible to discriminate dark cells from other epithelial cells lining the vestibular endolymphatic spaces. From birth, the Na,K-ATPase beta2 isoform was expressed in the lateral and basal cell membranes of a subset of cells located in the utricular wall, at the base of the cristae ampullaris and was identified as dark cells. From birth, anti-cytokeratins labelled all the cells forming the epithelial lining, including the dark cells, while anti-vimentin labelled the underlying mesenchymal cells. From postnatal day 10, anti-S100A6 labelled subepithelial cells exclusively located underneath the dark-cell areas and were identified as vestibular melanocyte-like cells. From birth, Fontana staining evidenced fine melanin granules in the subepithelial layer. The amount of melanin granules increased during the first month. Melanin distribution was closely associated with the region where S100A6-positive cells were located. The cell-specific antigen expression in the dog dark-cell areas was clearly comparable to that of the dog stria vascularis previously described. The present investigation also suggested an earlier histological and immunohistological maturity in the dark-cell areas than in the stria vascularis of dogs. This preliminary morphological description of the normal dark-cell areas in dogs by means of immunomarkers may be instrumental in studying pathological processes involving the fluid-secreting structures in vestibular endorgans.

Evaluation of stool antigen detection for diagnosis of Helicobacter pylori infection in adults

OBJECTIVE

The aims of this study were to evaluate the performance of Helicobacter pylori stool antigen test in the diagnosis of H. pylori infection.

METHOD

The study included 63 out patients attending the ULB-Lothier Clinic between January 1 and July 31, 2002. They underwent an upper endoscopy, as well as biopsies for histological examination and for culture of H. pylori. Stool samples of these patients were collected either the day of the endoscopy or within 24 hours and tested for H. pylori antigen (HpSA Test)

RESULTS

The mean age of study patients included 29 men and 34 women was 51(+/- :16) years. H. pylori infection was detected in 29 cases (46 %) by culture and histology, and in 31 cases (49.2 %) by detection of the antigen in the feces. In 27 patients, all methods were positive whereas 5 in they provided discrepant results. Compared to the reference methods (culture and histology), the HpSA test had a sensitivity of 96.5% and a specificity of 91.2%. PPV of 90.3% and NPV of 96.8%.

CONCLUSION

The good correlation found between the results of the HpSA test and the methods based on endoscopy supports its use as an alternative to invasive methods of diagnosis of H. pylori infection and therapeutic follow-up.

The fate of dendritic cells in a mouse model of liver ischemia/reperfusion injury

Ischemia/reperfusion during liver transplantation triggers a complex cascade of inflammatory events that may lead to organ dysfunction. Herein, we investigated the consequences of hepatic ischemia/reperfusion on liver dendritic cells. Liver damage was documented by increased levels of serum alanine aminotransferase and by histopathology showing large areas of hepatocyte cytolysis. MHC class II+ CD45-B220 F4/80 dendritic cells were detected in necrotic areas 20 hours after reperfusion. Dendritic cells freshly isolated from reperfused livers displayed a mature phenotype characterized by upregulated expression of B7 costimulatory molecules; MHC-class II, and CD1d molecules. As shown by real-time PCR, IL-10, and TGF-beta mRNA accumulated in liver dendritic cells isolated after reperfusion, whereas IL-12p40 mRNA levels were decreased and IFN-gamma mRNA levels were unchanged. These results suggest that hepatic ischemia/reperfusion results in maturation of dendritic cells, which preferentially produce inhibitory cytokines.

S100A5: a marker of recurrence in WHO grade I meningiomas

Some WHO grade I intracranial meningiomas resected from the same sites and with the same quality of resection (Simpson's grading scale) recur, while others do not. The reasons for this variability in occurrence of recurrence have not yet been determined. We therefore investigated the prognostic recurrence value of seven biological markers on a series of completely resected WHO grade I meningiomas. For this purpose, we analysed a series of 33 WHO grade I meningiomas totally resected between 1980 and 1990 (a follow-up of 10 years), including 14 cases of recurrence. The fixed tumour material from each meningioma was submitted to histochemical analyses targeting galectin-3 and its binding sites, the S100A5, S100A6 and S100B proteins, and cathepsin-B and -D. The levels of expression were assessed semi-quantitatively (in terms of the staining intensity and the labelling index) and submitted to uni- and multivariate analyses. Of all the markers investigated, only S100A5 expression can be associated with any significant prognostic value in the matter of recurrence. More particularly, the meningiomas with high levels of S100A5 staining intensity either did not recur, or recurred later than those with a low immunopositive S100A5 intensity (P = 0.004). Cox regression analyses demonstrated that this latter marker was associated with significant prognostic values independent of the patients' ages. Furthermore, the combination of the patients' ages and S100A5 staining intensity permitted the identification of a group with a particularly high risk of recurrence, that is, the patients younger than 55 and with meningiomas exhibiting low S100A5 intensities (P = 0.001). In conclusion, the S100A5 protein could play a role in the recurrence of totally resected WHO grade I meningiomas.

[External auditory meatus adenocarcinoma]

We report the case of a man presenting a deafness and a hemorrhagic ear discharge since one year. CT scanner and MRI reveal an invasive tumoral lesion of the external auditory meatus (EAM) expending into the posterior fossa. After surgery the diagnosis of high grade ceruminal gland adenocarcinoma is established whereas the malignancy was not obvious on earlier biopsy. Cancers arising in the EAM are uncommon and are essentially representating by squamous cell cancers and basal cell cancers. The precise diagnosis of a glandular tumor is a challenge for the pathologist because the limits between benign and malignant tumors are not obvious. Integration of clinical and radiological behavior and the histology of the tumor is necessary for a early diagnosis and a complete surgery.

CD40 expression on human pancreatic duct cells: role in nuclear factor-kappa B activation and production of pro-inflammatory cytokines

AIMS/HYPOTHESIS

Human pancreatic duct cells are closely associated with islet beta cells, and contaminate islet suspensions transplanted in Type 1 diabetes mellitus patients. Activated duct cells produce cytotoxic mediators and possibly contribute to the pathogenesis of Type 1 diabetes mellitus or islet graft rejection. As CD40 transduces activation signals involved in inflammatory and immune disorders, we investigated CD40 expression on duct cells and their response to CD40 engagement.

METHODS

CD40 expression on human pancreatic duct cells was analysed by flow cytometry and immunohistochemical analyses. To assess the function of CD40 expression on duct cells, activation of the transcription factor nuclear factor-kappa B was determined using electrophoretic mobility shift assay and ELISA. Cytokine mRNA levels were quantified by real-time RT-PCR, and protein levels by Luminex technology.

RESULTS

Isolated human pancreatic duct cells and Capan-2 cell lines were found to express constitutively CD40. The expression of CD40 on duct cells was confirmed in vivo on human normal and pathological pancreatic specimens. CD40 ligation on Capan-2 cells induced rapid nuclear factor-kappa B activation, and supershift assays demonstrated that p50/p65 heterodimers and p50/p50 homodimers were present in the activated complexes in the nucleus. This activation was accompanied by tumour necrosis factor-a and interleukin-1beta mRNA accumulation. Tumour necrosis factor-alpha protein secretion was confirmed in CD40-activated Capan-2 cells and in isolated human pancreatic duct cells.

CONCLUSIONS/INTERPRETATION

Interaction between activated T lymphocytes expressing CD40 ligand and duct cells expressing CD40 may contribute to the immune responses involved in Type 1 diabetes mellitus and islet graft rejection. Interfering with CD40-mediated duct cell activation could alleviate beta cell damage of immune origin.

[Histologic and ultrastructural features of cell death both physiological and induced by two different teratogens in branchial arches of mouse embryo]

AIM OF THE STUDY

To observe and compare cell death process both physiological and associated with the administration of two different teratogens (irradiation and retinoic acid) inside cephalic mesectoderm.

MATERIAL AND METHODS

Irradiated mice: 2 Gy were administered to E 9 embryos. Retinoic acid: 60 mg/kg were gave to E 8 or E 9 embryos. E 9 - 9.5 and E 10 embryos were removed. E 9 - E 9.5 and E 10 control specimens were collected. We used semi-thin sections and ultra-thin sections observed with transmission electron microscope.

RESULTS

The major process is apoptosis, which is increased in experimental embryos compared to control specimens. However, autophagy was observed in retinoic acid-treated embryos, while necrosis can rarely occurs after irradiation.

CONCLUSION

If the common process seems to be apoptosis, both teratological models differs owing to their respective secondary features. These differences should be explained by the specific pathogenesis of both teratological agents: ligand-receptor reaction and Hox system disruption in retinoic acid administration, direct aggression against DNA and diffuse cell death process following irradiation. Furthermore, congenital malformations induced by these teratogens are quite different. This can be partially explained by a specific blow of different cellular subpopulations.

Cathepsin B, D and K expression in adamantinomatous craniopharyngiomas relates to their levels of differentiation as determined by the patterns of retinoic acid receptor expression

AIMS

To investigate the potential predictive value of cathepsins B, D and K in a series of 51 adamantinomatous craniopharyngiomas. While almost always benign, craniopharyngiomas exhibit a high propensity to recur postsurgically and biological markers are therefore needed to predict their recurrence. We have previously demonstrated the potential predictive value of retinoic acid receptors (RARs) (Lefranc et al., J. Neurosurg. 2003; 98; 145-153).

METHODS AND RESULTS

Computer-assisted microscopy was used to determine quantitatively the immunohistochemical levels of expression of the alpha, beta and gamma RAR subtypes and cathepsins B, D and K. The levels of expression of cathepsin D and of cathepsin B correlated significantly with the levels of expression of RARbeta. The levels of expression of cathepsin K correlated significantly with the levels of expression of RARgamma.

CONCLUSIONS

Recurrent adamantinomatous craniopharyngiomas are characterized by low levels of RARbeta and high levels of RARgamma. The tendency to recurrence seems, at least partly, to relate to the fact that (i) craniopharyngiomas with low levels of RARbeta express low levels of cathepsin D, and (ii) craniopharyngiomas with high levels of RARgamma express high levels of cathepsin K.

[The pathology department]

The evolution of the Laboratory of Pathology at Erasmus Hospital is directly related to the morphological diagnosis integration in the medico-surgical organization of the Hospital. Such integration is based on the creation of links between the Laboratory of Pathology and the clinical departments and necessitates permanent adaptations to new complementary technology. Immunohistochemical methods were gradually included in the surgical morphological diagnosis. Currently, new markers from molecular biology are needed to obtain accurate pathological diagnosis. We observe an increasing hyperspecialization of the morphological classification with complete integration of such biological markers leading to the necessity of carrying out collegial diagnosis. The development of the telepathology technology permits international collegial diagnosis. According to its central position the Laboratory of Pathology plays an important part in the development of the clinical and fundamental research. The research subjects of the Laboratory of Pathology concern diagnostic and prognostic evaluation in colic cancers, sarcomas, brain tumors and HPV related tumors endometriosis.