Overview of recent advances in the classification of ependymomas in WHO CNS5 classification: Simplified approach to their integrated diagnosis

Ependymomas can arise along the entire neuraxis; however, they possess site-specific unique molecular alterations and a methylome pattern which is directly related with the prognostic outcomes. Since 2016, when the updated fourth edition of World Health Organization (WHO) classification of tumors of the central nervous system was published, it has been emphasized to classify ependymomas by anatomic site and molecular signatures associated genetic alterations so that classification of the disease reflects its underlying biology. In continuation, the fifth edition of the WHO classification of CNS tumors introduces major changes, including site-specific molecular profiles as the basis of classifying ependymomas. Furthermore, an integrated tier system of reporting is recommended for better clinical correlation and predicting outcomes. WHO grading can still be included in a specific tier, along with molecular markers.

Pediatric-type diffuse low grade gliomas: Histomolecular profile and practical approach to their integrated diagnosis according to the WHO CNS5 classification

Department of Pathology and Lab Medicine, All India Institute of Medical Sciences, Bhubaneswar, Odisha, India

Department of Neuropathology Laboratory, Neurosciences Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India

World Health Organization Classification of Tumors of the Central Nervous System 5th Edition (WHO CNS5): What's new?

The latest fifth edition of the World Health Organization classification of central nervous system tumors (WHO CNS5) has been built on the prior WHO 2016 classification as well as recommendations put forward by seven updates of the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT). Various new tumor types and subtypes have been recognized which are of clinical significance. Tumor groups have been restructured and the nomenclature of some tumor types has also been revised. The use of terms 'entity' and 'variant' have been replaced by 'type' and 'subtype'. Significant changes have been introduced in the grading of tumors viz. use of Arabic numerals, grading within individual tumor types and combined histological and molecular grading. The terms 'Not otherwise specified' and 'Not elsewhere classified' can now be used for all tumor types. WHO CNS5 also for the first time endorses the use of DNA methylation profiling for the diagnosis of some tumor types/subtypes. Finally, the importance of combining histology with molecular parameters is emphasized for the “layered reporting” and “integrated diagnosis”, which will provide valuable diagnostic, prognostic, and predictive information, as well as for some entities, suggest targeted therapies.

Anaplastic large cell lymphoma presenting as an endobronchial mass with lung involvement in an adolescent boy

Primary endobronchial presentation of anaplastic large cell lymphoma is rare in the paediatric age group. We present a 12-year-old boy with breathlessness, fever, cough and weight loss, who was misdiagnosed as a case of tuberculosis and started on antitubercular therapy, which showed no improvement. Chest X-ray showed a completely opacified left hemithorax and chest computed tomography revealed a mass encircling the left main bronchus with collapse– consolidation of the left lung. Fibreoptic bronchoscopy revealed a growth in the left main bronchus. Subsequently, fine-needle aspiration cytology and biopsy from the mass confirmed it to be a malignancy consistent with anaplastic large cell lymphoma. Metastatic work-up revealed no other sites of involvement. Chemotherapy resulted in rapid and complete regression of the tumour. No evidence of local or distant recurrence was reported after 18 months of follow-up. Clinicians and pathologists should be aware of this presentation as prompt diagnosis and treatment can give promising results. This case highlights the importance of timely tissue diagnosis in patients with non-resolving pyrexia and organ lesions on imaging.

Uterine tumor resembling ovarian sex cord tumor: A series of six cases displaying varied histopathological patterns and clinical profiles

Introduction: Uterine tumors resembling ovarian sex cord tumor (UTROSCT) are a unique group of neoplasms with diverse morphology and immunophenotypic characteristics, coexpressing sex cord, epithelial, and smooth-muscle markers. To date, less than 100 cases have been reported and there is paucity of data concerning their clinical behavior. Materials and Methods: All cases of uterine body tumors diagnosed over a period of two and a half years (2016-2018) were retrieved. Histopathological features were reviewed and extended panel of immunohistochemistry was performed to identify cases of UTROSCTs. Results: Six cases of UTROSCTs were identified with a median age of 46.5 years. Four of them presented with menorrhagia, while two with postmenopausal bleeding including one with a history of carcinoma breast. Three of these cases were initially misdiagnosed as endometrial stromal sarcoma and adenocarcinomas. They all underwent hysterectomy with bilateral salpingo-oophorectomy. Conclusion: It is considered a tumor with low malignant potential; however, one out of six cases (16.7%) in our study showed metastasis, within 1 year of diagnosis. It is important to recognize this entity as it mimics a wide range of both benign and malignant tumors. Molecular pathogenesis and exact management protocols remain elusive due to rarity,hence, multi-institutional studies are warranted.

Composite pleomorphic xanthoastrocytoma-ganglioglioma; assessing and addressing the dilemma of differential expression of neuronal markers: Case report with diagnostic perspective

We report the case of a 5-year-old male child presenting with seizures for 4 months. Magnetic resonance imaging (MRI) revealed a cortical-based solid cystic lesion in the right parietal lobe. Histopathological examination showed a tumour comprised of spindled glial fibrillary acid protein (GFAP) positive neoplastic cells interspersed with bizarre pleomorphic cells showing nuclear pseudoinclusions and intermingled dysplastic ganglion cells variably immunopositive for synaptophysin, chromogranin, Neu-N and immunonegative for neuron filament protein (NFP). This report highlights the occurrence of the rare composite pleomorphic xanthoastrocytoma-ganglioglioma and the vagaries of immunohistochemical analysis in highlighting neuronal differentiation in such a case setting. In addition, to the best of our knowledge this is the youngest patient till date to present with this entity.