[Show abstract][Hide abstract] ABSTRACT: The standard therapy regimen of conventional osteosarcoma includes neoadjuvant chemotherapy followed by surgical resection and postoperative chemotherapy. The percentage of necrotic tissue following induction chemotherapy is assessed by using the Huvos grading system, which classifies patients as "poor responders" (PR) and "good responders" (GR). The aim of this study was to identify molecular markers expressed differentially between good and poor responders to neoadjuvant chemotherapy in order to predict the response to chemotherapy in conventional osteosarcomas before beginning treatment.
BMC Cancer 08/2014; 14(1):606. · 3.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rosai-Dorfman disease of the central nervous system is extremely rare and difficult to diagnose also for pathologists. We describe three unusual cases of meningeal Rosai-Dorfman disease and illustrate the difficulties of preoperative and pathological diagnosis. We retrospectively analyzed three patients who underwent surgery for a suspected meningioma for whom the final diagnosis was Rosai-Dorfman disease of the central nervous system. Pathological initial diagnosis was schwannoma, lymphoplasmacyte-rich meningioma, or inflammatory tumor, but final diagnosis in all cases was Rosai-Dorfman disease. These cases underline the preoperative and pathological difficulties of such diagnosis. Pathologists and physicians should be aware of the occurrence of such rare localization of this disease and should think about this differential diagnosis in lymphocyte-rich meningeal tumors mimicking, clinically and radiologically, a meningioma. Communication of significant previous medical history to pathologists and careful examination of slides with appropriate medical history and the use of S100 antibody in the diagnosis of meningeal tumors mimicking Rosai-Dorfman disease could lower the rate of misdiagnosis.
Annals of Hematology 12/2013; · 2.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: L’esame anatomopatologico dei tumori del sistema nervoso centrale è cruciale per la gestione dei pazienti. Esso si basa sulla citologia, sull’esame istopatologico standard dopo l’inclusione in paraffina e su tecniche complementari, come l’immunoistochimica, la biologia molecolare ed eccezionalmente la microscopia elettronica. Un esame estemporaneo è, a volte, realizzato per assicurarsi della rappresentatività del materiale tumorale in caso di biopsie stereotassiche. Un frammento tumorale potrà anche essere congelato per costituire una tumoroteca, se esiste abbastanza materiale. La diagnosi istopatologica consiste nel determinare il tipo di proliferazione tumorale e nel fornire degli elementi prognostici. La classificazione dell’Organizzazione Mondiale della Sanità (OMS) 2007 dei tumori del sistema nervoso centrale distingue i tumori primitivi e quelli secondari. Fra i tumori primitivi, sono i tumori neuroepiteliali, tra cui si distinguono i gliomi, a essere i più frequenti. Ciascuno di essi è definito da criteri istopatologici precisi che permettono di fornire una diagnosi e degli elementi prognostici sotto forma di un grading, a volte controverso, in particolare per i gliomi infiltranti. Numerosi lavori di biologia molecolare hanno evidenziato delle alterazioni genetiche che permettono di descrivere dei modelli di progressione verso la malignità, in particolare per i gliomi infiltranti e i meningiomi. Questi dati si aggiungono alla diagnosi anatomopatologica.
[Show abstract][Hide abstract] ABSTRACT: Glial and glioneuronal tumors in children and adult demonstrate distinctive clinical, neuroradiological and molecular features depending on the pathological subtype and within a same subgroup according to the age. In children, gliomas are mainly located in the infratentorial part of the brain. They are most often benign and circumscribed but infiltrative tumors with dismal prognosis are recorded within the pons (DIGP) or the thalamus. Glioblastomas are very rare in children. In contrast, gliomas in adult mainly occur in the cerebral hemispheres and the most frequent subtype is glioblastoma. Glioneuronal tumors mainly occurred in children and young adults. In addition, although pilocytic astrocytomas, pleomorphic xanthoastrocytomas and gangliogliomas are classified into different subgroups according to the WHO 2007 classification, these tumors demonstrate similar neuroradiological findings: they are cystic with contrast enhancement of a mural nodule. Major advances have been made these last five years in the discovery of some master genes that are involved in gliomagenesis and point out differences between children and adults. In adults, infiltrative gliomas can be classified into two major subgroups depending on the existence or not of IDH mutations. IDH-dependent gliomagenesis encompasses diffuse grade II and grade III (they can also show additional molecular alterations such as TP53 mutation or 1p19q codeletion) and secondary glioblastomas. IDH-independent gliomagenesis include triple negative grade II gliomas, gliomatosis cerebri (grade III) and de novo glioblastomas. Pilocytic astrocytomas, pleomorphic xanthoastrocytomas and gangliogliomas share in common BRAF alterations. However, KIAA1549-BRAF fusion characterizes pilocytic astrocytomas whereas V600E BRAF mutation is mainly recorded in pleomorphic xanthoastrocytomas and gangliogliomas.
[Show abstract][Hide abstract] ABSTRACT: I tumori del sistema nervoso periferico (SNP) comprendono dei tumori benigni, essenzialmente rappresentati dagli schwannomi e dai neurofibromi, e dei tumori maligni, raggruppati sotto il termine di tumori maligni della guaina dei nervi periferici (malignant peripheral nerve sheath tumours [MPNST]). Questi tumori sono sporadici o si sviluppano nell’ambito di una facomatosi. La neurofibromatosi di tipo 1 (NF1) si caratterizza per la presenza di neurofibromi e di eventuali tumori maligni della guaina dei nervi periferici. Gli schwannomi multipli sono un criterio diagnostico della neurofibromatosi di tipo 2 (NF2). Gli schwannomi o neurinomi sono dei tumori ben delimitati che realizzano una massa eccentrica sul tragitto di un nervo. In istologia, la proliferazione è costituita da cellule di Schwann organizzate in fasci compatti (zone A di Antoni) o in zone più lasse ed edematose (zone B di Antoni). I nuclei delle cellule possono allinearsi e realizzare delle palizzate che delimitano degli spazi che corrispondono ai noduli di Vérocay, numerosi nelle zone A di Antoni. Le cellule tumorali esprimono la proteina S100 in immunoistochimica. I neurofibromi sono dei tumori mal delimitati, spesso cutanei. Quando si sviluppano sul tragitto di un nervo, essi determinano un aumento di volume fusiforme. La proliferazione tumorale è costituita da cellule di Schwann, da cellule perineurali e da fibroblasti organizzati su un fondo mixoide. Il trattamento degli schwannomi e dei neurofibromi consiste in un’exeresi chirurgica. I tumori maligni delle guaine dei nervi periferici si sviluppano in più del 50% dei casi in un contesto di NF1. Macroscopicamente si tratta di tumori a crescita rapida che determinano frequentemente dei rimaneggiamenti necroticoemorragici e un marcato potere di invasione locoregionale e, in seguito, generale. L’istologia mostra una proliferazione di cellule fusiformi con un’alternanza di zone compatte e di zone più lasse. Le cellule presentano delle atipie citonucleari ed esprimono la proteina S100 in modo più eterogeneo e più debole che nei tumori benigni. Si tratta, in genere, di tumori ad alto grado di malignità e la loro prognosi è riservata. Più recentemente, sono stati descritti dei MPNST a basso grado di malignità. Nel 15% dei casi, esistono degli aspetti morfologici inconsueti, con un aspetto epitelioide oppure una differenziazione divergente: tumore di Triton e MPNST ghiandolare. Il trattamento rimane essenzialmente chirurgico. In alcuni casi una chemioterapia sarà discussa in una riunione di concertazione interdisciplinare.
[Show abstract][Hide abstract] ABSTRACT: La conducta médica inicial ante el hallazgo de un tumor óseo primario es fundamental, pues permite definir la mejor estrategia diagnóstica y terapéutica. Desde luego, la asistencia médica ha de ser multidisciplinaria. Esto conduce a la elección del método de biopsia diagnóstica y a la vía de acceso más adecuada. En el menor tiempo posible, la biopsia se enviará en «estado fresco» al patólogo, quien ha de repartir el material (fijación, congelación, etc.) según la cantidad, la calidad o los presuntos diagnósticos. Se conocen unas 50 formas de tumores óseos primarios, distribuidas en 12 clases principales. Algunas de estas formas, sobre todo los condrosarcomas, cuentan con una clasificación histopronóstica específica.
[Show abstract][Hide abstract] ABSTRACT: GNAS (guanine nucleotide-binding protein/α-subunit) mutations that induce the activation of G-protein α-subunit participate in the pathogenesis of fibrous dysplasia. The aim of this study was to evaluate the sensitivity and specificity of GNAS mutations in fibrous dysplasia and other fibro-osseous lesions, to assess the value of investigating this mutation in the diagnosis of fibro-osseous lesions. We studied 91 cases of fibrous dysplasia. The quality and/or quantity of genomic DNA were suitable for molecular analysis for 51 cases of fibrous dysplasia. GNAS mutations were investigated by three techniques: high-resolution melting (exon 8), allele-specific PCR (exons 8 and 9) and/or direct DNA sequencing (exons 8 and 9). Fibrous dysplasia samples were classified blind to the GNAS mutation status into six histological subtypes as conventional, fibro-involutive, osteosclerosing, cementifying, osteocartilaginous and with prominent aneurysmal cystic changes. We also studied 14 cases of low-grade osteosarcoma, 21 cases of ossifying fibroma, 3 cases of osteofibrous dysplasia, 1 case of osseous dysplasia of the jawbone and 1 post-traumatic lesion of the ribs. Twenty-three cases of fibrous dysplasia (45%) showed mutations of codon 201 (exon 8, p.R201H or p.R201C). No mutation was found on codon 227 (exon 9). GNAS mutations in conventional fibrous dysplasia were detected in the same proportion (47%) as in the other histological subtypes (47%, P=0.96), regardless of sex (P=0.44), age (P=0.90) and location (P=1). GNAS mutations were not detected in any other fibro-osseous lesions. The GNAS mutation was thus specific to fibrous dysplasia in the context of fibro-osseous lesions. The particular mosaicism of mutant and non-mutant cells within the lesion or the existence of other mutations not already described could explain the lack of GNAS mutation in cases of fibrous dysplasia. Investigating this mutation may constitute a valuable complementary diagnostic tool, despite its low sensitivity, particularly in unconventional morphologically different subtypes of fibrous dysplasia.
Modern Pathology 02/2013; 26. · 6.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Solitary Fibrous Tumours (SFT) and haemangiopericytomas (HPC) are rare meningeal tumours that have to be distinguished from meningiomas and more rarely from synovial sarcomas. We recently found that ALDH1A1 was overexpressed in SFT and HPC as compared to soft tissue sarcomas. Using whole-genome DNA microarrays, we defined the gene expression profiles of 16 SFT/HPC (9 HPC and 7 SFT). Expression profiles were compared to publicly available expression profiles of additional SFT or HPC, meningiomas and synovial sarcomas. We also performed an immunohistochemical (IHC) study with anti-ALDH1 and anti-CD34 antibodies on Tissue Micro-Arrays including 38 SFT (25 meningeal and 13 extrameningeal), 55 meningeal haemangiopericytomas (24 grade II, 31 grade III), 163 meningiomas (86 grade I, 62 grade II, 15 grade III) and 98 genetically confirmed synovial sarcomas.
ALDH1A1 gene was overexpressed in SFT/HPC, as compared to meningiomas and synovial sarcomas. These findings were confirmed at the protein level. 84% of the SFT and 85.4% of the HPC were positive with anti-ALDH1 antibody, while only 7.1% of synovial sarcomas and 1.2% of meningiomas showed consistent expression. Positivity was usually more diffuse in SFT/HPC compared to other tumours with more than 50% of tumour cells immunostained in 32% of SFT and 50.8% of HPC. ALDH1 was a sensitive and specific marker for the diagnosis of SFT (SE = 84%, SP = 98.8%) and HPC (SE = 84.5%, SP = 98.7%) of the meninges. In association with CD34, ALDH1 expression had a specificity and positive predictive value of 100%.
We show that ALDH1, a stem cell marker, is an accurate diagnostic marker for SFT and HPC, which improves the diagnostic value of CD34. ALDH1 could also be a new therapeutic target for these tumours which are not sensitive to conventional chemotherapy.
[Show abstract][Hide abstract] ABSTRACT: Pilocytic astrocytomas (PAs) are characterized by an excellent prognosis although several factors of adverse outcome have been reported. The mitogen-activated protein kinase pathway plays a major role in their tumorigenesis. AIM: To report a series of 148 PAs in children to define clinico-pathological and biological prognostic factors. METHODS: Clinical data were collected from patient files and mail inquiry. Pathological specimens were centrally reviewed. The three major KIAA1549:BRAF fusion subtypes were analysed by Reverse Transcription - Polymerase Chain Reaction (RT-PCR) in a subset of 47 frozen cases and by Fluorescence In Situ Hybridization on formalin fixed paraffin embedded tissue in 23 cases. Tumour location, age at surgery, extent of surgical removal, histological subtype and KIAA1549:BRAF fusion by RT-PCR were searched for prognostic significance. RESULTS: Pilomyxoid astrocytoma (PMA) and the hypothalamo-chiasmatic (H/C) location were associated with a worse prognosis (P<0.001 for OS and P=0.001 for PFS). Patients who underwent complete surgical excision had a better OS (P=0.004) and a longer PFS (P<0.001) than the others. Age was also a strong prognostic factor for OS but not for PFS. Infants (<1 year) and young children (<3 years) had a much worse outcome than the others (P<0.001 and P=0.004 respectively). KIAA1549:BRAF fusion status was not predictive of outcome. CONCLUSION: This study highlights the good prognostic factors of PAs but H/C PA remains a subgroup with dismal prognosis associated with young age, PMA variant and incomplete surgery. Search for KIAA1549:BRAF fusion in tumours with PA pattern is recommended even though the prognostic impact is still unclear.
Neuropathology and Applied Neurobiology 12/2012; · 4.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Dysembryoplastic Neuroepithelial Tumours (DNT) are benign brain lesions arising during childhood that are characterized by early onset partial seizures, no neurological deficit and cortical location. Pathological diagnosis is easy when the glioneuronal element is present. Its absence might lead to the diagnosis of non-specific DNT or low-grade glioma (LGG). Objective: The aim of this retrospective study was to analyse clinicopathological and molecular features of a series of cortical tumours, in order to find diagnostic and prognostic markers to better custom treatment next. Methods: Twenty four children with cortical neuroepithelial tumour were included. Clinical and radiological data were collected. Histological diagnosis was reviewed for all patients. 1p19q and p53 status were obtained by FISH and immunohistochemistry respectively. IDH1-2 gene mutations were assessed by DNA sequencing. CGH-array was performed in 6/24 samples. Results: We recorded 13 DNT and 11 cortical LGG. Median age at surgery was 11.5 years. Overall survival was 100% and event-free survival at 10 years was 70%. No tumour displayed chromosomal alteration or 1p19q deletion or p53 expression. Only one patient with grade-II oligoastrocytoma had an IDH1 mutation. No statistical difference was found between the two populations in terms of age, sex, tumour location, type of surgical resection, disease progression and clinical status at last follow-up. Only the occurrence of septations on preoperative MRI was significantly associated with pathological features of DNT. Conclusion: Patients with DNT and cortical LGG share excellent outcome. Our genetic analysis could not distinguish DNT from LGG. In particular, CGH-array analysis was strictly normal in both tumor types. In attempt to find molecular markers, diagnosis of these lesions remains difficult when the glioneuronal element is lacking.
Current topics in medicinal chemistry 09/2012; · 4.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Adult grade II low-grade gliomas (LGG) are classified according to the WHO as astrocytomas, oligodendrogliomas or mixed gliomas. TP53 mutations and 1p19q codeletion are the main molecular abnormalities recorded, respectively, in astrocytomas and oligodendrogliomas and in mixed gliomas. Although IDH mutations (IDH1 or IDH2) are recorded in up to 85 % of low-grade gliomas, IDH negative gliomas do occur. We have searched for p53 expression, 1p19q codeletion and IDH status (immunohistochemical detection of the common R132H IDH1 mutation and IDH direct sequencing). Internexin alpha (INA) expression previously recorded to be associated with 1p19q codeletion (1p19q+) gliomas was also analysed. Low-grade gliomas were accurately classified into four groups: group 1, IDH+/p53-/1p19q-; group 2, IDH+/p53-/1p19q+; group 3, IDH+/p53+/1p19q-; and group 4, triple negative gliomas. In contrast to the WHO classification, this molecular classification predicts overall survival on uni- and multivariate analysis (P = 0.001 and P = 0.007, respectively). Group 4 carries the worst prognosis and group 2 the best. Interestingly, p53 +/INA- expression predicts lack of 1p19q codeletion (specificity 100 %, VPP 100 %). The combined use of these three molecular markers allow for an accurate prediction of survival in LGG. These findings could significantly modify LGG classification and may represent a new tool to guide patient-tailored therapy. Moreover, immunohistochemical detection of p53, INA and mR132H IDH1 expression could represent an interesting prescreening test to be performed before 1p19q codeletion, IDH1 minor mutation and IDH2 mutation detection.
Journal of Neuro-Oncology 08/2012; 110(2):205-13. · 3.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Preoperative diffusion-weighted MRI (DW-MRI) has been described as an efficient method to differentiate good and poor responders to chemotherapy in osteosarcoma patients. A DW-MRI performed earlier during treatment could be helpful in monitoring chemotherapy.
To assess the accuracy of DW-MRI in evaluating response to chemotherapy in the treatment of osteosarcoma, more specifically at mid-course of treatment.
This study was carried out on a prospective series of adolescents treated for long-bone osteosarcoma. MR examinations were performed at diagnosis (MRI-1), at mid-course of chemotherapy (MRI-2), and immediately before surgery (MRI-3). A DW sequence was performed using diffusion gradients of b0 and b900. The apparent diffusion coefficients (ADC1, ADC2, ADC3, respectively), their differentials (ADC2 - ADC1 and ADC3 - ADC1), and their variation (ADC2 - ADC1/ADC1 and ADC3 - ADC1/ADC1) were calculated for each of these three time points.
Fifteen patients were included. Patients with no increase in ADC showed a poor response to chemotherapy on their histology results. At mid-course, the three calculated values were significantly different between good and poor responders. ADC2 - ADC1 enabled us to detect, with 100% specificity, four out of seven of the poor responders. There was no significant difference in the values at MRI-3 between the two groups.
DW-MRI performed both at baseline and mid-course of neoadjuvant chemotherapy is an efficient method to predict further histological response of osteosarcoma. This method could be used as an early prognostic factor to monitor preoperative chemotherapy.
[Show abstract][Hide abstract] ABSTRACT: Diffuse ganglioneuromatosis of the digestive tract is a rare condition, especially in children. It is frequently associated with multiple endocrine neoplasia type 2b and less commonly with neurofibromatosis type 1 (NF1). We report the case of an 8-month-old baby presenting with vasoactive intestinal polypeptide (VIP)-secreting diffuse ganglioneuromatosis affecting the small intestine and the colon and responsible for severe hydric diarrhea. Postoperatively the infant's symptoms resolved and the serum VIP level was normal. NF1 was clinically suspected and then confirmed through genetic testing. Two years later, the child developed an optic pathway glioma, another tumor frequently associated with NF1.
Annales de Pathologie 02/2012; 32(1):58-64. · 0.29 Impact Factor