Histopathological diagnosis of lymphomas represents a challenge requiring either expertise or centralised review, and greatly depends on the technical process of tissue sections. Hence, we developed ...an innovative deep-learning framework, empowered with a certainty estimation level, designed for haematoxylin and eosin-stained slides analysis, with special focus on follicular lymphoma (FL) diagnosis. Whole-slide images of lymph nodes affected by FL or follicular hyperplasia were used for training, validating, and finally testing Bayesian neural networks (BNN). These BNN provide a diagnostic prediction coupled with an effective certainty estimation, and generate accurate diagnosis with an area under the curve reaching 0.99. Through its uncertainty estimation, our network is also able to detect unfamiliar data such as other small B cell lymphomas or technically heterogeneous cases from external centres. We demonstrate that machine-learning techniques are sensitive to the pre-processing of histopathology slides and require appropriate training to build universal tools to aid diagnosis.
Histiocytic sarcoma (HS) is a rare aggressive hematologic neoplasm that can be associated with low-grade B cell lymphoma. The development of both neoplasms is currently being considered a ...transdifferentiation mechanism but remains elusive. We report the case of a 65-year-old patient with synchronous development of peritoneal/abdominal HS and grade 1–2 follicular lymphoma (FL). Cytogenetic analysis and targeted next-generation sequencing of both FL and HS tumors identified common genomic alterations such as IGH-BCL2 rearrangement, CREBBP and KMT2D, and aberrations of chromosomes 9q and 19q. However, only the HS tumor had a KRAS mutation while the lymph node involved by FL harbored a TNFAIP3 mutation and both tumors also showed distinct chromosomal alterations. This report strengthens the hypothesis of a common lymphoid progenitor which accumulates genetic alterations leading to two different hematologic malignant diseases with significantly distinct prognoses.
Although perfusion magnetic resonance imaging (MRI) is widely used to identify pseudoprogression, this advanced technique lacks clinical reliability. Our aim was to develop a parameter assessing the ...hypervascularized fraction of glioblastomas based on volume analysis of dynamic susceptibility contrast-enhanced MRI and evaluate its performance in the diagnosis of pseudoprogression. Out of 25 patients, 11 (44%) were classified with pseudoprogression and 14 (56%) with true progression based on the Response Assessement in Neuro-Oncology criteria. rCBVmax was lower for pseudoprogression (3.4 vs. 7.6; p = 0.033) on early follow-up MRI. %rCBV>2, was lower for pseudoprogression on both initial (57.5% vs. 71.3%; p = 0.033) and early follow-up MRIs (22.1% vs. 51.8%; p = 0.0006). On early follow-up MRI, %rCBV>2 had the largest area under the curve for the diagnosis of pseudoprogression: 0.909 0.725-0.986. The fraction of hypervascularization of glioblastomas as assessed by %rCBV>2 was lower in tumours that subsequently developed pseudoprogression both on the initial and early follow-up MRIs. This fractional parameter may help identify pseudoprogression with greater accuracy than rCBVmax.
Glioblastoma is the most aggressive primary brain tumor, which almost systematically relapses despite surgery (when possible) followed by radio-chemotherapy temozolomide-based treatment. Upon ...relapse, one option for treatment is another chemotherapy, lomustine. The efficacy of these chemotherapy regimens depends on the methylation of a specific gene promoter known as MGMT, which is the main prognosis factor for glioblastoma. Knowing this biomarker is a key issue for the clinician to personalize and adapt treatment to the patient at primary diagnosis for elderly patients, in particular, and also upon relapse. The association between MRI-derived information and the prediction of MGMT promoter status has been discussed in many studies, and some, more recently, have proposed the use of deep learning algorithms on multimodal scans to extract this information, but they have failed to reach a consensus. Therefore, in this work, beyond the classical performance figures usually displayed, we seek to compute confidence scores to see if a clinical application of such methods can be seriously considered. The systematic approach carried out, using different input configurations and algorithms as well as the exact methylation percentage, led to the following conclusion: current deep learning methods are unable to determine MGMT promoter methylation from MRI data.
Glioblastomas (GB) are malignant brain tumors with poor prognosis despite treatment with surgery and radio/chemotherapy. These tumors are defined by an important cellular heterogeneity and notably ...contain a subpopulation of GB-initiating cells (GIC), which contribute to tumor aggressiveness, resistance, and recurrence. Some integrins are specifically expressed by GICs and could be actionable targets to improve GB treatment. Here, integrin β8 (ITGB8) was identified as a potential selective target in this highly tumorigenic GIC subpopulation. Using several patient-derived primocultures, it was demonstrated that ITGB8 is overexpressed in GICs compared with their differentiated progeny. Furthermore, ITGB8 is also overexpressed in GB, and its overexpression is correlated with poor prognosis and with the expression of several other classic stem cell markers. Moreover, inhibiting ITGB8 diminished several main GIC characteristics and features, including self-renewal ability, stemness, migration potential, and tumor formation capacity. Blockade of ITGB8 significantly impaired GIC cell viability via apoptosis induction. Finally, the combination of radiotherapy and ITGB8 targeting radiosensitized GICs through postmitotic cell death. IMPLICATIONS: This study identifies ITGB8 as a new selective marker for GICs and as a promising therapeutic target in combination with chemo/radiotherapy for the treatment of highly aggressive brain tumors.
Craniopharyngioma is a rare condition in children, but it is the most frequent tumor that occurs in the hypothalamic pituitary region. Chemical meningitis has been described as an uncommon ...postoperative complication, but no chemical meningitis due to a spontaneous rupture leading to craniopharyngioma diagnosis in children has been reported.
This is a case of a 13-year-old boy presenting with fever, vomiting and headache for two days. The CT scan revealed a suprasellar lesion, and lumbar puncture showed aseptic meningitis. The cerebral MRI suggested a craniopharyngioma and the cerebrospinal fluid cholesterol concentration was abnormally high. A thorough medical history indicated some visual disturbance, which improved at the onset of meningitis, and an inflection of the growth curve. The anatomopathological analysis of the tumor confirmed the diagnosis of craniopharyngioma.
This case is the first to report the discovery of a craniopharyngioma with meningoencephalitis caused by the rupture of a craniopharyngioma cyst in a child. Diagnosis was facilitated by determining the cholesterol level in the cerebrospinal fluid, as well as fine anamnesis to identify visual and growth disturbances.
An increasing number of sarcomas displaying a primitive, monomorphic spindle cell phenotype have been shown to harbor recurrent gene fusions, including biphenotypic sinonasal sarcoma (SNS). Occurring ...in the sinonasal area of middle‐aged patients, SNS is a locally aggressive tumor harboring in 90% of cases recurrent gene fusions involving the PAX3 gene, in which the chimeric transcription factor induces an aberrant dual myogenic and neural phenotype. Here, we report an unusual oropharyngeal monomorphic spindle cell sarcoma in a 53‐year‐old man that revealed a novel RREB1–MKL2 gene fusion by RNA sequencing with the Illumina TruSight RNA Fusion Panel. The gene fusion was validated by RT‐PCR. Although the tumor location is unusual (but head and neck seated), most of the other clinical, morphologic, immunophenotypic (focal combined expression of S100 protein, SMA, desmin, and myogenin) and oncogenic data suggest that this biphenotypic “oropharyngeal” sarcoma is closely related to the biphenotypic SNS spectrum. Notably, the RREB1–MKL2 chimeric transcription factor encoded by this fusion gene produced an increase in MKL2 expression, which regulates both neural and myogenic differentiation, mimicking the crucial role of PAX3 reported in SNS oncogenesis. NGS and especially RNA sequencing may be used to identify new candidate fusion oncogenes in soft tissue tumors, which would help in updating the existing classification. In turn, this would lead to better therapeutic management of patients.
The YAP1 (Yes1 Associated Transcriptional Regulator) gene encodes the Yap1 protein, a downstream effector of the Hippo tumor suppressor pathway and functions as a regulator of TEAD-dependant ...transcription 3. The literature review of ST-EPN-YAP1 suggests a favorable outcome, with only 1 case out of 30 reported dying during the surgery 2–4. ...three cases were treated only with gross total resection and were alive without recurrence at the end of follow-up (from 7 to 16 years after the initial surgery) 2. Following our observation, it seems that the YAP1-MAMLD1 fusion is less frequent in adult populations compared to pediatric cases (95% vs 33%, respectively). Since YAP1-MAML2 fusion is shared by some meningiomas and now ependymomas in the CNS, and because different gene partners of YAP1 have been reported in these two tumor types, the FISH analysis for YAP1 represents a good diagnostic tool which should be part of the neuropathologist’s routine panel of techniques.
The cIMPACT-NOW Update 7 has replaced the WHO nosology of "ependymoma, RELA fusion positive" by "Supratentorial-ependymoma, C11orf95-fusion positive". This modification reinforces the idea that ...supratentorial-ependymomas exhibiting fusion that implicates the C11orf95 (now called ZFTA) gene with or without the RELA gene, represent the same histomolecular entity. A hot off the press molecular study has identified distinct clusters of the DNA methylation class of ZFTA fusion-positive tumors. Interestingly, clusters 2 and 4 comprised tumors of different morphologies, with various ZFTA fusions without involvement of RELA. In this paper, we present a detailed series of thirteen cases of non-RELA ZFTA-fused supratentorial tumors with extensive clinical, radiological, histopathological, immunohistochemical, genetic and epigenetic (DNA methylation profiling) characterization. Contrary to the age of onset and MRI aspects similar to RELA fusion-positive EPN, we noted significant histopathological heterogeneity (pleomorphic xanthoastrocytoma-like, astroblastoma-like, ependymoma-like, and even sarcoma-like patterns) in this cohort. Immunophenotypically, these NFκB immunonegative tumors expressed GFAP variably, but EMA constantly and L1CAM frequently. Different gene partners were fused with ZFTA: NCOA1/2, MAML2 and for the first time MN1. These tumors had epigenetic homologies within the DNA methylation class of ependymomas-RELA and were classified as satellite clusters 2 and 4. Cluster 2 (n = 9) corresponded to tumors with classic ependymal histological features (n = 4) but also had astroblastic features (n = 5). Various types of ZFTA fusions were associated with cluster 2, but as in the original report, ZFTA:MAML2 fusion was frequent. Cluster 4 was enriched with sarcoma-like tumors. Moreover, we reported a novel anatomy of three ZFTA:NCOA1/2 fusions with only 1 ZFTA zinc finger domain in the putative fusion protein, whereas all previously reported non-RELA ZFTA fusions have 4 ZFTA zinc fingers. All three cases presented a sarcoma-like morphology. This genotype/phenotype association requires further studies for confirmation. Our series is the first to extensively characterize this new subset of supratentorial ZFTA-fused ependymomas and highlights the usefulness of ZFTA FISH analysis to confirm the existence of a rearrangement without RELA abnormality.
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