Machine Learning Decision Tree Models for Differentiation of Posterior Fossa Tumors Using Diffusion Histogram Analysis and Structural MRI Findings.

We applied machine learning algorithms for differentiation of posterior fossa tumors using apparent diffusion coefficient (ADC) histogram analysis and structural MRI findings. A total of 256 patients with intra-axial posterior fossa tumors were identified, of whom 248 were included in machine learning analysis, with at least 6 representative subjects per each tumor pathology. The ADC histograms of solid components of tumors, structural MRI findings, and patients' age were applied to construct decision models using Classification and Regression Tree analysis. We also compared different machine learning classification algorithms (i.e., naïve Bayes, random forest, neural networks, support vector machine with linear and polynomial kernel) for dichotomized differentiation of the 5 most common tumors in our cohort: metastasis (n = 65), hemangioblastoma (n = 44), pilocytic astrocytoma (n = 43), ependymoma (n = 27), and medulloblastoma (n = 26). The decision tree model could differentiate seven tumor histopathologies with terminal nodes yielding up to 90% accurate classification rates. In receiver operating characteristics (ROC) analysis, the decision tree model achieved greater area under the curve (AUC) for differentiation of pilocytic astrocytoma (p = 0.020); and atypical teratoid/rhabdoid tumor ATRT (p = 0.001) from other types of neoplasms compared to the official clinical report. However, neuroradiologists' interpretations had greater accuracy in differentiating metastases (p = 0.001). Among different machine learning algorithms, random forest models yielded the highest accuracy in dichotomized classification of the 5 most common tumor types; and in multiclass differentiation of all tumor types random forest yielded an averaged AUC of 0.961 in training datasets, and 0.873 in validation samples. Our study demonstrates the potential application of machine learning algorithms and decision trees for accurate differentiation of brain tumors based on pretreatment MRI. Using easy to apply and understandable imaging metrics, the proposed decision tree model can help radiologists with differentiation of posterior fossa tumors, especially in tumors with similar qualitative imaging characteristics. In particular, our decision tree model provided more accurate differentiation of pilocytic astrocytomas from ATRT than by neuroradiologists in clinical reads

Antigenic expression in human choroid plexus carcinoma : report of two cases

Neoplasias provenientes do epitélio de revestimento do plexo coróide são inco-muns, tendo sido descritos 6 padrões morfológicos. O padrão anaplásico, também denominado carcinoma do plexo coróide, é o de menor freqüência e pode dar metastases fora do SNC. A distinção histológica desses tumores, particularmente da variedade anaplásica, com outras neoplasias primárias e metastáticas no SNC pode ser difícil. O uso de técnicas imunocitoquimicas em parafina tem-se mostrado útil no esclarecimento das linhagens tumorais. Os papilomas do plexo coróide têm, no entanto, sido objeto de controvérsia, por sua complexa expressão antigênica. Usando a técnica de imunoperoxidase (sistema avidina-biotina-peroxidase) pesquisaram-se, em dois casos da variedade anaplásica, os seguintes marcadores: proteína glial fibrilar ácida (GFAP) com anticorpo monoclonal e policlonal; ceratinas de 40-50kDa, ceratinas de 60-70kDa (callus ceratina), enolase neuronal específica (NSE) e proteína S-100, com anticorpos monoclonais. Os dois tumores mostraram positividade para NSE, proteína S-100 e ceratina de 40-50kDa; uma das duas neoplasias mostrou diferenciação glial, revelando positividade para GFAP tanto com anticorpo monoclonal quanto policlonal.Primary neoplasms of choroid plexus are rare. Six morphological variants have been described: papillary, cystic, acinar, mucus-secreting, oncocytic, and anaplastic. The anaplastic variant, the so-called choroid plexus carcinoma, is the rarest of all and can metastasize. The differential diagnosis of the anaplastic variant of choroid plexus neoplasms with adenocarcinomas, melanomas and indifferentiated neoplasms can be troublesome chiefly in adults. The now large use of immunocytochemical techniques in tissue section has become a powerful tool in the analysis of cell lineages, tumoral and non-tumoral. Nevertheless, the choroid plexus neoplasms have shown a complex and a somewhat confusing pattern of antigenic expression. In two choroid plexus carcinomas (one localized in the right lateral ventricle from a boy of 1 year and 9 months old, and the other localized in the left lateral ventricle from a girl of 3 years old) the following antigens were searched (using the avidin-biotin-peroxydase complex): glial fibrillary acidic protein (GFAP) with monoclonal and polyclonal antibodies; cytokeratins of 40-50kDa, cytokeratins of 60-70kDA (callus cytokeratin), neuronal specific enolase (NSE) and S-100 protein with monoclonal antibodies. The two neoplasms showed immunoreactivity against NSE, S-100 protein and cytokeratin of 40-50kDA The neoplasm of the boy exhibited glial differentiation having immunoreactivity against GFAP with monoclonal and polyclonal antibodies

Focal Spot, Summer 1999

https://digitalcommons.wustl.edu/focal_spot_archives/1082/thumbnail.jp

The 2007 WHO Classification of Tumours of the Central Nervous System

The fourth edition of the World Health Organization (WHO) classification of tumours of the central nervous system, published in 2007, lists several new entities, including angiocentric glioma, papillary glioneuronal tumour, rosette-forming glioneuronal tumour of the fourth ventricle, papillary tumour of the pineal region, pituicytoma and spindle cell oncocytoma of the adenohypophysis. Histological variants were added if there was evidence of a different age distribution, location, genetic profile or clinical behaviour; these included pilomyxoid astrocytoma, anaplastic medulloblastoma and medulloblastoma with extensive nodularity. The WHO grading scheme and the sections on genetic profiles were updated and the rhabdoid tumour predisposition syndrome was added to the list of familial tumour syndromes typically involving the nervous system. As in the previous, 2000 edition of the WHO ‘Blue Book’, the classification is accompanied by a concise commentary on clinico-pathological characteristics of each tumour type. The 2007 WHO classification is based on the consensus of an international Working Group of 25 pathologists and geneticists, as well as contributions from more than 70 international experts overall, and is presented as the standard for the definition of brain tumours to the clinical oncology and cancer research communities world-wide

Target cells of human adenovirus type 12 in subtentorial brain tissue of newborn mice. I. Cyto-histomorphologic and immunofluorescent microscopic studies In vivo

Human adenovirus type 12 (Ad 12) was inoculated through subtentorial route into inbred newborn mice (C3H/BifB/Ki), and sequential changes of the brain and tumor induction were examined by histological and immunofluorescent methods. Two days after virus inoculation, Ad 12 specific tumor antigen (fluorescent T-antigen) appeared in the cells of ependymal and subventricular matrix layers, choroid plexuses and leptomeninges in the subtentorial as well as the supratentorial brains. After 10 days, these fluorescent positive cells decreased gradually in number but still remained focally beneath the ependyma. Sixty days later, early tumor nodules were detected in the same regions in which remained the fluorescent cells. After 107 days, neurological signs and well-developed tumors were noted in 25 of 63 (30.1%) mice examined. In the cerebellum, both of T-antigens and tumors were limited around the IVth ventricle, but not in the granular layers. Histomorphologically, the tumors were of primitive neuroectodermal origin and consisted of the cells resembling immature matrix cells in the subventricular zone. These findings strongly suggest that the virus has a selective affinity to the remaining matrix cells, but not to cerebellar granular cells, at least, in newborn mice.</p

Pitfalls and Artifacts in Nuclear Imaging Studies

In interpreting scintillation images, one often is confronted with a variety of deviations from the typically normal study that need not represent definite pathology. Apart from normal anatomic variants in the position, shape, or configuration of an organ, one must also be prepared to appreciate alterations due to the radiodiagnostic agent employed and aberrations caused by faulty or improperly used instruments. Additionally, physiologic and/or functional changes associated with specific organ studies have provided a major source of error in routine image interpretation. It is the purpose of this article to acquaint (or reacquaint, as the case may be) the reader with many of these problems so that they may easily recognize them and, one hopes, improve their overall interpretative abilities. The discussion will follow the lines of general considerations relating to instrumentation and radiopharmaceuticals followed by specific organ considerations. In this type of review, some intentional as well as some unintentional omissions may appear. The author hopes that most of the common sources of error have been included. Undoubtedly, some readers may think of other problems that they may personally have been confronted with

Diffusion, Perfusion, and Histopathologic Characteristics of Desmoplastic Infantile Ganglioglioma.

We present a case series of a rare tumor, the desmoplastic infantile ganglioglioma (DIG) with MRI diffusion and perfusion imaging quantification as well as histopathologic characterization. Four cases with pathologically-proven DIG had diffusion weighted imaging (DWI) and two of the four had dynamic susceptibility contrast imaging. All four tumors demonstrate DWI findings compatible with low-grade pediatric tumors. For the two cases with perfusion imaging, a higher relative cerebral blood volume was associated with higher proliferation index on histopathology for one of the cases. Our results are discussed in conjunction with a literature review

CHARACTERISTICS OF INDIVIDUALS UNDERGOING PANEL GENETIC TESTING FOR PRIMARY BRAIN TUMORS

Background. Currently, there are no genetic testing guidelines for patients with a primary brain tumor (PBT). This population is largely understudied in terms of the family history, tumor grade, pathology, and their relation to genetic contribution. Our aim was to describe patient-specific characteristics and family histories across mutation-positive, negative, and variant of uncertain significance (VUS) cohorts based on cancer-panel genetic test results among patients with a PBT. Methods. Subjects were referred for multi-gene panel testing between March 2012 and June 2016. Clinical data were ascertained from test requisition forms. The incidence of pathogenic mutations (including likely pathogenic) and VUS’s were calculated for each gene and patient cohort. Results. Almost all tumors were glial (n=293, 53%) or meningeal pathology (n=222, 40%). Age of diagnosis differed significantly between glial and meningeal tumors (pCHEK2 (20/104), BRCA2 (13/104), PMS2 (10/104), TP53 (8/104), and APC (8/104). Of 165 patients with available family history information, nearly all (n=157, 95%) reported a family history of some cancer. Conclusions. Our data suggest PBTs can be the primary presenting cancer in hereditary syndromes with a known PBT risk. While pathology is helpful in narrowing down the differential diagnosis, patients’ pathology can be atypical in relation to their hereditary cancer syndrome. Family history evaluations are a beneficial risk assessment modality, particularly until testing criteria are developed for PBTs. Further research is necessary for the development of genetic testing criteria in the PBT population and more robust identification of at-risk individuals