China
Africa
Explore chapters and articles related to this topic
Paper 3
Published in Amanda Rabone, Benedict Thomson, Nicky Dineen, Vincent Helyar, Aidan Shaw, The Final FRCR, 2020
Amanda Rabone, Benedict Thomson, Nicky Dineen, Vincent Helyar, Aidan Shaw
The location of this lesion is not typical for an ependymoma. They arise from glial cells lining the ventricles or spinal canal. In children they are usually infratentorial affecting the fourth ventricle, but they can be supratentorial in adults.
Central Nervous System
Published in Pat Price, Karol Sikora, Treatment of Cancer, 2020
Ependymoma is a glioma arising from the ependymal cells that normally line the cerebral ventricles and the central canal of the spinal cord. They can arise at any site, usually in association with the ventricular system, but are most common in the posterior fossa, where they present with obstruction or with posterior fossa syndrome. The incidence of intracranial tumors is greatest in young children. Imaging usually shows a well-circumscribed tumor with variable contrast enhancement in the characteristic location. They comprise fewer than 2% of all primary CNS tumors. In adults, most are located in the spine, whereas in children, the majority are in the brain, most commonly posterior fossa. Survival is worse in younger patients and with supratentorial location and high-grade disease.
Ependymoma in Childhood and Adolescence
Published in David A. Walker, Giorgio Perilongo, Roger E. Taylor, Ian F. Pollack, Brain and Spinal Tumors of Childhood, 2020
The 2016 WHO2,4 classification defines grades I–III, with classic ependymoma (grade II) and anaplastic ependymoma (grade III) being more prevalent (Box 15.1). A new entity of supratentorial ependymoma has been added, defined by the presence of a RELA fusion gene, comprising 80% of supratentorial ependymomas. Consistent histological grading of ependymoma has proven difficult as a spectrum of pathological features exists, preventing reliable discrimination between grades II and III.2,18 In turn, the relationship between grade and outcome remains controversial.2,18 An international consensus has proposed new diagnostic features which will be tested in the next SIOP ependymoma trial.18 It is likely that grade will be determined by a combined morphological and molecular profile in the future.22
Paediatric posterior fossa tumour resection rates in a small volume centre: the past decade’s experience
Published in British Journal of Neurosurgery, 2021
Harsh Bhatt, Muhammad Imran Bhatti, Chirag Patel, Paul Leach
Patients with ‘other complications’ included one boy with a fourth-ventricular pilocytic astrocytoma ventilated on paediatric intensive care unit (PICU) for respiratory dysfunction 24-h post-operatively, and eventually having a tracheostomy. This patient’s tumour was located in the inferior 4th ventricle, extending through the foramen magnum into the upper cervical cord and displacing the medulla. Their delayed post-operative respiratory dysfunction was felt to be secondary to left-sided lung collapse, consolidation and pneumomediastinum. Brainstem compression by the tumour and oedema perhaps contributed to poor cough and resultant consolidation/collapse. For medulloblastomas, it included three patients: one with respiratory depression ventilated on PICU for a week post-operatively, who also had an EVD inserted following a CSF leak, a child with posterior fossa (PF) swelling four days post-operatively which needed PF decompression and insertion of an EVD, and one patient with apnoeic episodes secondary to raised intracranial pressure (ICP) needing an EVD. For the ependymoma patients, it involved one case with hyponatraemia and seizures which were both addressed in the post-operative period uneventfully.
Primary ependymoma of the retropubic space in a male patient
Published in Ultrastructural Pathology, 2020
Elif Tasar Kapakli, Kemal Kosemehmetoglu, Figen Kaymaz, Bulent Akdogan, Mustafa Ozmen, Dilek Ertoy Baydar
Currently, there are no specific immunohistochemical or genetic markers for the diagnosis of ependymoma; therefore, ultrastructural findings, in addition to the presented microscopic and immunohistochemical features, can play a pivotal role to reach to the ultimate decision in particular ependymomas in unusual locations. Ependymomas ultrastructurally demonstrate acellular zones composed of large numbers of closely packed, filament-rich, cytoplasmic processes around small vessels representing pseudo rosettes. Luminal borders contain slender, curving microvilli, and variable numbers of cilia. The presence of cilia withing true or intracytoplasmic lumina is found up to 75% of the cases and it is an invaluable finding in especially ENEs, thus worths to be searched for. Lumens are lined by cells connected with unusually long junctions at their apical margins. Especially, the presence of long, intermediate intercellular junctions is quite characteristic of ependymomas.9 Ultimately, light microscopic, immunohistochemical, and ultrastructural features altogether were consistent with the diagnosis of ENE.
Can differences in linear energy transfer and thus relative biological effectiveness compromise the dosimetric advantage of intensity-modulated proton therapy as compared to passively scattered proton therapy?
Published in Acta Oncologica, 2018
Drosoula Giantsoudi, Judith Adams, Shannon MacDonald, Harald Paganetti
In patients treated for infratentorial ependymoma, sensitive organs at risk (OARs), such as the brainstem and spinal cord are located at very close proximity, usually anteriorly and adjacent to, if not within, the target volume. Nevertheless, the ideal proton beam arrangement for sparing the cochlea, neuroendocrine structures and temporal lobes consists of posterior–anterior and oblique posterior–lateral fields, placing the distal end of the treatment fields towards or within the brainstem and/or spinal cord, which has been associated with elevated LET and RBE values in the brainstem [7]. Prescribed doses for ependymoma treatment approach tolerance for these critical structures and even a small increase in biological effects could lead to an increased risk of injury with potential life-altering complications for a patient. Under these considerations, the purpose of this study is to compare the three-dimensional (3D) LET distributions between PS and PBS proton therapy delivery techniques and study the potential effect in RBE-weighted dose distribution for ependymoma patients.