Friday, September 21, 2018

Multinodular and vacuolating neuronal tumor,WHO grade I

The patient is a middle-aged male with a temporal lobe mass. Histopathology shows a low-grade ganglion cell tumor with clustered ganglion cells with a vacuolated neuropil background. The fragmented nature of the specimen precludes identification of a nodular architecture. The diagnosis is multinodular and vacuolating neuronal tumor, WHO grade I. This entity is a cousin of gangliocytoma.

Thursday, September 20, 2018

A WHO grade IV diagnosis in the face of a low-grade histophenotype: a difficult situation for the surgical neuropathologist

This midbrain mass in a 33-year-old patient has low-grade histology (minimal mitoses, low MIB-1 cell cycling index, and a single Rosenthal fiber), yet it harbors the H3 K27M mutation. Perivascular lymphocytes were present, but ganglioglioma was ruled out. So, the following diagnosis was rendered: diffuse midline glioma, H3 K27M mutant, WHO grade IV.  Other molecular changes included loss of p16 (CDKN2a) and loss of PTEN and 10 centromere, consistent with monosomy for chromosome 10. The discordance between histopathology and molecular findings can make the diagnostician squeamish about rendering a high-grade diagnosis. But, sometimes, this is where we find ourselves.

Tuesday, September 18, 2018

Monday, September 17, 2018

Best Post of August 2018 - Omalu puts a religious spin on his assessment of the football: "It is not of God."

The next in our "Best of the Month" series comes from August 8, 2018:
“We shouldn’t let children play [football] because we are damaging their brains and robbing them of their humanity. That is a fact.” That's what Dr. Bennet Omalu had to say to a reporter associate with Sojourners, a faith-based organization. In the recently released article from Sojourners, Omalu said that football is a sport "not of God". A committed Catholic, Omalu  says that he lets "the Spirit of God percolate into my being... Everything I do, I do through the eyes of faith.”

Bennet Omalu, MD
Omalu is best known for the startling discovery he made after performing an autopsy on former NFL player Mike Webster. As chronicled in the 2015 film Concussion, with Will Smith starring as Omalu, the then-medical examiner in Pittsburgh found Webster had chronic traumatic encephalopathy and related it to Webster's years of playing football.

Wednesday, September 12, 2018

Best Post of July 2018: What is the nodulus?

The next in our "Best of the Month" series come from July 16, 2018:

The nodulus is the lobule of the cerebellar vermis that, together with the flocculus of each hemisphere, forms the flocculonodular lobe.

Tuesday, September 11, 2018

Circadian Rhythm Gene May Serve as Target for Glioblastoma Therapies

Scientists from the Virginia Tech Carilion Research Institute say a gene involved in the body's circadian rhythms is a potential target for therapies for glioblastoma.
Their discovery (“Casein Kinase 1 Epsilon Regulates Glioblastoma Cell Survival”), published in Scientific Reports, points to a subtype of a particular gene that apparently is enabling the survival of cancer cells, although it is more commonly associated with circadian rhythms.
“In our previous work, we identified casein kinase 1 ε (CK1ε, also known as CSNK1E) as a potential survival factor in glioblastoma. However, how CK1ε controls cell survival remains elusive and whether targeting CK1ε is a possible treatment for glioblastoma requires further investigation. Here we report that CK1ε was expressed at the highest level among six CK1 isoforms in glioblastoma and enriched in high-grade glioma, but not glia cells. Depletion of CK1ε remarkably inhibited the growth of glioblastoma cells and suppressed self-renewal of glioblastoma stem cells, while having limited effect on astrocytes,” write the investigators.

Friday, September 7, 2018

A case of posterior cortical atrophy

Posterior cortical atrophy (PCA) is a neurodegenerative syndrome that is characterised by progressive decline in visuospatial, visuoperceptual, literacy, and praxic skills. The progressive neurodegeneration affecting parietal, occipital, and occipitotemporal cortices that underlies PCA is attributable to Alzheimer's disease in most patients. However, alternative underlying causes, including dementia with Lewy bodies, corticobasal degeneration, and prion disease, have also been identified, and not all patients with PCA have atrophy on clinical imaging. (Crutch, S. J., Lehmann, M., Schott, J. M., Rabinovici, G. D., Rossor, M. N., & Fox, N. C. (2012). Posterior cortical atrophyLancet Neurology11(2), 170-178)

This is a case of a 60-year-old female with PCA:

Although there is diffuse neocortical atrophy, note the prominent occipital lobe atrophy

Tau stain of temporal lobe section highlights Alzheimer pathology

Pallor of the substantia nigra was noted, and Lewy bodies noted microscopically (see inset)

Alpha-synuclein staining showed neocortical Lewy bodies (here in the frontal lobe)

The final diagnosis was Alzheimer disease and Diffuse Neocortical Lewy Body Disease in the setting of Posterior Cortical Atrophy.

Thursday, August 23, 2018

A case of Alexander disease

Alexander disease is a progressive and often fatal leukodystrophy wherein innumerable Rosenthal fibers form. Caused by mutation in the gene encoding GFAP, Alexander disease can be inherited in an autosomal dominant manner, but typically arises de novo.