Imaging yielded a differential diagnosis of embryonal tumor, ependymoma, and hemorrhagic choroid plexus papilloma. Histomorphology shows acute hemorrhage and hemosiderin-stained choroid plexus with a rounded, hobnail-shaped epithelial surface. The rounded surface distinguishes this normal choroid plexus from the epithelium of a choroid plexus papilloma, which has a flat surface.
I discuss issues pertaining to the practice of neuropathology -- including nervous system tumors, neuroanatomy, neurodegenerative disease, muscle and nerve disorders, ophthalmologic pathology, neuro trivia, neuropathology gossip, job listings and anything else that might be of interest to a blue-collar neuropathologist.
Tuesday, May 31, 2016
Choroid plexus hemorrhage mimicking an intraventricular neoplasm in a newborn
Imaging yielded a differential diagnosis of embryonal tumor, ependymoma, and hemorrhagic choroid plexus papilloma. Histomorphology shows acute hemorrhage and hemosiderin-stained choroid plexus with a rounded, hobnail-shaped epithelial surface. The rounded surface distinguishes this normal choroid plexus from the epithelium of a choroid plexus papilloma, which has a flat surface.
Sunday, May 29, 2016
Saturday, May 28, 2016
Friday, May 27, 2016
Summary of the Major Changes in the 2016 WHO Classification of CNS Tumors
Major restructuring of medulloblastomas, with incorporation of
genetically defined entities
Addition of brain invasion as a criterion for atypical meningioma
Restructuring of solitary fibrous tumor and hemangiopericytoma (SFT/HPC) as one entity and adapting a grading system to accommodate this change
Expansion and clarification of entities included in nerve sheath tumors, with addition of hybrid nerve sheath tumors and separation of melanotic schwannoma from other schwannomas
Expansion of entities included in hematopoietic/lymphoid tumors of the CNS (lymphomas and histiocytic tumors)
Addition of the following newly recognized entities, variants and patterns:
- IDH-wildtype and IDH-mutant glioblastoma (entities)
- Diffuse midline glioma, H3 K27M–mutant (entity)
- Embryonal tumour with multilayered rosettes, C19MC-altered (entity)
- Ependymoma, RELA fusion–positive (entity)
- Diffuse leptomeningeal glioneuronal tumor (entity)
- Anaplastic PXA (entity)
- Epithelioid glioblastoma (variant)
- Glioblastoma with primitive neuronal component (pattern)
- Multinodular and vacuolated pattern of ganglion cell tumor (pattern)
Deletion of the following entities, variants and terms:
- Gliomatosis cerebri
- Protoplasmic and fibrillary astrocytoma variants
- Cellular ependymoma variant
- “Primitive neuroectodermal tumour” terminology
(Adapted from table 2 in Louis DN et al. The 2016 World Health Organization Classification of Tumors of the Central Nervous System: a summary. Acta Neuropathol (2016) 131:803–820.
Addition of brain invasion as a criterion for atypical meningioma
Restructuring of solitary fibrous tumor and hemangiopericytoma (SFT/HPC) as one entity and adapting a grading system to accommodate this change
Expansion and clarification of entities included in nerve sheath tumors, with addition of hybrid nerve sheath tumors and separation of melanotic schwannoma from other schwannomas
Expansion of entities included in hematopoietic/lymphoid tumors of the CNS (lymphomas and histiocytic tumors)
Addition of the following newly recognized entities, variants and patterns:
- IDH-wildtype and IDH-mutant glioblastoma (entities)
- Diffuse midline glioma, H3 K27M–mutant (entity)
- Embryonal tumour with multilayered rosettes, C19MC-altered (entity)
- Ependymoma, RELA fusion–positive (entity)
- Diffuse leptomeningeal glioneuronal tumor (entity)
- Anaplastic PXA (entity)
- Epithelioid glioblastoma (variant)
- Glioblastoma with primitive neuronal component (pattern)
- Multinodular and vacuolated pattern of ganglion cell tumor (pattern)
Deletion of the following entities, variants and terms:
- Gliomatosis cerebri
- Protoplasmic and fibrillary astrocytoma variants
- Cellular ependymoma variant
- “Primitive neuroectodermal tumour” terminology
(Adapted from table 2 in Louis DN et al. The 2016 World Health Organization Classification of Tumors of the Central Nervous System: a summary. Acta Neuropathol (2016) 131:803–820.
Thursday, May 26, 2016
Orbital rhabdomyosarcoma
Orbital rhabdomyosarcoma with cross striations and rhabdomyoblasts. Arrow points to eosinophilic strap cell with cross striations. Rhabdomyosarcoma is the most common malignant orbital tumor of childhood.
(Adapted from Eye Pathology: An Atlas and Text [2nd edition] by Ralph C. Eagle)
(Adapted from Eye Pathology: An Atlas and Text [2nd edition] by Ralph C. Eagle)
Wednesday, May 25, 2016
Friday, May 20, 2016
AANP Meeting Presidential Symposium Speaker: Neil Cashman, MD
From the American Association of Neuropathologists front office:
Neil Cashman, MD |
AANP is very excited
to have Dr. Neil Cashman present at this year’s Presidential Symposium on
Sunday, June 19. His talk will be on Seeding and Propagation of SOD1
Misfolding in Amyotrophic Lateral Sclerosis.
Dr. Neil Cashman is a neurologist-neuroscientist working in
neurodegeneration and neuroimmunology. His special areas of work are the
motor neuron diseases, particularly amyotrophic lateral sclerosis, and the
amyloid encephalopathies, including prion illnesses and Alzheimer’s disease. He
is Professor of Medicine at the University of British Columbia, where he holds
the Canada Research Chair in Neurodegeneration and Protein Misfolding Diseases.
He is the Founder and Chief Scientific Officer of ProMIS Neurosciences in
Toronto.
Special honors include the Jonas Salk Prize (2000), his Tier
1 Canada Research Chair in at the UBC (2005-2018), election to the Canadian
Academy of Health Sciences (2008), and Genome BC award for Scientific
Excellence (2012).
We look forward to Dr. Cashman’s discussion on ALS at the 92nd
Annual Meeting!
Monday, May 16, 2016
Finally!!! The new WHO CNS tumor classification book has been published
After months of anticipation, the new brain tumor WHO classification book is here! You can order it at this web address.
Thanks to Dr. Mark Cohen for alerting me to this development.
Thanks to Dr. Mark Cohen for alerting me to this development.
Thursday, May 12, 2016
MYB-QKI fusion: A novel alteration that may define and drive pediatric angiocentric glioma
Angiiocentric glioma |
This post is adapted from "Highlights from the Literature", edited by Kenneth Aldape in the journal Neuro-Oncology 18(6), 761–763, 2016
Reference:
Bhandopadhayay P, Ramkissoon LA, Jain P, et al. MYB-QKI rearrangements in angiocentric glioma drive tumorigenicity through a tripartite mechanism. Nat Genet 2016;48(3):273–282.
Thursday, May 5, 2016
Absence of Lymphatic Vessels in PCNSL May Contribute to Confinement of Tumor Cells to the Central Nervous System
Did you ever wonder why primary CNS lymphoma stays restricted to the CNS? Over the years, I have been asked that by several students and trainees, but I could never give a good answer. An article published online in the Journal of Neuropathology and Experimental Neurology on May 3rd points toward an answer. The phenomenon may be related to the unique lymphatic drainage system of the CNS. The brief report, entitled Absence of Lymphatic Vessels in PCNSL May Contribute to Confinement of Tumor Cells to the Central Nervous System, is authored by Martina Deckert and colleagues from the Department of Neuropathology at the University Hospital of Cologne (Germany) and the Institute of Human Genetics at Christian-Albrechts-University Kiel (Germany).
Deckert and colleagues investigated PCNSL for the presence of lymphatic vessels using immunohistochemistry for Lyve-1, podoplanin, and Prox-1 expression in a series of 20 intraparenchymal PCNSL biopsies in comparison with 8 dural/meningeal-based foci of systemic diffuse large B-cell lymphoma (DLBCL) as well as 20 glioblastomas lacking any contact with the meninges.
All PCNSLs and glioblastomas investigated lacked lymphatic vessels as evidenced by absence of immunohistochmemical lymphatic vessel markers. However, dural/meningeal DLBCL foci harbored lymphatic vessels that expressed Lyve-1 (3/8 tumors), podoplanin (5/8 tumors), and Prox-1 (5/8
tumors) in areas where the tumors had invaded the fibrous tissue of the dura. Taken together, the immunohistochemical panel demonstrated lymphatic vessels in 7 out of 8 (87.5%) of the DLBCLs investigated.
The authors note that although cerebrospinal fluid drains to lymph nodes through a variety of routes, these passages are presumably too small to allow passage of large neoplastic lymphocytes.
This report leaves one glaring question unanswered: If one investigated glioblastomas that did have contact with the dura/meninges, would those show evidence of lymphatic vessels? If so, why do those glioblastomas not metastatize to areas outside the CNS?
Deckert and colleagues investigated PCNSL for the presence of lymphatic vessels using immunohistochemistry for Lyve-1, podoplanin, and Prox-1 expression in a series of 20 intraparenchymal PCNSL biopsies in comparison with 8 dural/meningeal-based foci of systemic diffuse large B-cell lymphoma (DLBCL) as well as 20 glioblastomas lacking any contact with the meninges.
Absence of lymphatic vessels in PCNSL demonstrated by negative Prox-1 staining (inset: human tonsils serve as positive control) |
tumors) in areas where the tumors had invaded the fibrous tissue of the dura. Taken together, the immunohistochemical panel demonstrated lymphatic vessels in 7 out of 8 (87.5%) of the DLBCLs investigated.
The authors note that although cerebrospinal fluid drains to lymph nodes through a variety of routes, these passages are presumably too small to allow passage of large neoplastic lymphocytes.
This report leaves one glaring question unanswered: If one investigated glioblastomas that did have contact with the dura/meninges, would those show evidence of lymphatic vessels? If so, why do those glioblastomas not metastatize to areas outside the CNS?
Wednesday, May 4, 2016
Best Post of March 2016: A list of neuropathologists who are departmental chairs
The next in our "Best of the Month" series is from March 25, 2016. After the initial post, several readers wrote in to add to the original collection of names.
There is a disproportionate number of neuropathologists who are chairs of their departments. Some readers thought it would be interesting if a list of these chairs could be compiled. With the help of Mark Cohen, Bette Kleinschmidt-DeMasters, and Robert Mrak, a pretty comprehensive list has been assembled:
Douglas Anthony at Brown
Steven Carroll at Medical University of South Carolina
Eyas Hattab at University of Louisville
Alex Judkins at Children's Hospital Los Angeles
David Louis at Massachusetts General Hospital
Jenny Libien at SUNY Downstate
David Louis at Massachusetts General Hospital
Jenny Libien at SUNY Downstate
Thomas Montine currently at University of Washington and soon to be at Stanford
Edwin Monuki at the University of California Irvine
Robert Mrak at the University of Toledo
Amyn Rojiani at Augusta University
Kevin Roth at Columbia
John Schweitzer at East Tennessee State University
Also of note:
William Hickey at Dartmouth (acting chair of pharmacology and toxicology, former pathology chair)
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