Monday, September 28, 2009
Baylisascaris procyonis is an intestinal roundworm endemic to the US raccoon population. Humans are infected by ingestion of worm eggs in raccoon feces. The median age for human infection is just over one year old, consistent with the propensity of young children to explore their environment orally (surprising that this behavior has not been naturally selected out of humans over the millenia!). I came across only one report of clinical recovery after infection (reference 2). Otherwise, cerebral Baylisascariasis results in either severe neurologic damage or death. That being said, subclinical infection has been suggested by a study in Chicago, which found 30 (8%) of 389 children 1–4 years of age were seropositive for B. procyonis, although none had experienced symptoms (reference 3).
The most common cause of eosinophilic meningitis in the United States is the presence of a ventriculoperitoneal shunt; but worldwide it is infection by Angiostrongylus cantonensis. In addition to Bayliscaris procyonis, other infectious causes of eosinophilic meningitis include Toxocara spp., Gnathostoma spinigerum, and neurocysticercosis (source: reference 2).
1. Love S, et al, eds. Greenfield's Neuropathology, 8th edition. p. 1479.
2. Pai et al. Full recovery from Baylisascaris procyonis eosinophilic meningitis. Emerging Infectious Disease 13(6) p 928-30. June 2007
3. Brinkman WB, Kazacos KR, Gavin PJ, Binns HJ, Robichaud JD, O'Gorman M, et al. Seroprevalence of Baylisascaris procyonis (raccoon roundworm) in Chicago area children. In: Program and abstracts of the 2003 Annual Meeting of the Pediatric Academic Societies, Seattle, Washington; 2003 May 3–6. Abstract 1872. [cited 2007 Mar 29]. Available from http://www.abstracts2view.com/pasall/authorindex.php
Wednesday, September 23, 2009
Today I profile Dr. Craig Horbinski (pictured), a rising star in the neuropathology firmament. If you follow the neuropathology literature, you are sure to hear about Craig in the coming decades as he sure to make a big impact on the field. After a short biographical sketch, Craig answers a few of my questions:
Craig Horbinski hails from snowy Buffalo, NY, where he did both his undergraduate training in Biology at Canisius College and a combined MD, PhD at the State University of New York at Buffalo. Craig’s work as a graduate student was on mechanisms of dendrite growth, requiring a lot of microscopy and morphometric analyses. After a 1-year postdoctoral research fellowship studying Parkinson Disease at the University of Pittsburgh, he did 3-year Anatomic Pathology residency at UPMC. During this time Craig developed an interest in oncogenesis, particularly as his residency training exposed him to cutting-edge molecular diagnostic approaches to neoplasms. Thus, when continuing his training as a fellow in neuropathology at Pitt, he focused his research on both the molecular diagnostics of gliomas and mechanisms underlying gliomagenesis, as well as the application of telemedicine to neuropathology. Upon completion of his neuropathology fellowship in July of 2009, Craig joined the faculty at the University of Kentucky in Lexington as an Assistant Professor in Neuropathology, where he is continuing his work on gliomagenesis and molecular diagnostics as an independent principal investigator. Craig is married to Christy and has a 1-year old son, Cedric. He and Christy are slated to adopt a baby from China, probably by early 2010.
1. Why did you decide to become a neuropathologist?
I’ve been attracted to the neurosciences since my sophomore year of college, which featured a fantastic course on neurobiology. Since I was already committed to being a physician, I thought neurology was the way to go (neurosurgery was out of the question). But as I went through medical school I discovered the field of pathology, in particular neuropathology. To me it seemed the best way to scratch both the research and clinical itches (so to speak), as neuropathology lends itself particularly well to those with combined-degree training.
2. Name a couple of important professional mentors. Why were they important to you?
The first person I have to acknowledge is Dennis Higgins, my thesis advisor back at SUNY Buffalo. He was a real gem, a pure scientist whose passion for science was both inspiring and infectious. It’s not an exaggeration to say I learned how to think like a scientist from him. Tragically he died of pancreatic cancer a few years ago; I think he would have been pleased to see how things have gone for me thus far. The second key person is Clayton Wiley, the Director of Neuropathology at the University of Pittsburgh. While I learned science from Dennis, I learned grantsmanship and administration from Clayton. He’s one of those exceedingly rare people who managed to succeed at all four pillars of an academic physician’s life: research, clinical, administration, and teaching. Plus he’s mastered the art of staying out of political brouhahas—not a trivial accomplishment in a big academic center. Even more intolerable is that he’s a terrific guy, very approachable, with a sharp, self-deprecating wit. Anyone who wants to know how to survive as a physician-scientist ought to emulate Clayton.
3. What advice would you give to a pathology resident interested in doing a neuropathology fellowship?
Be sure you are flexible with where you want to live. The job market for neuropathology is pretty good right now, but since brain tumors are relatively uncommon, only medium-to-large cities can typically sustain neuropathologists. That is, unless you are planning on doing full-time clinical, with some general surgical path mixed in. Another word of caution goes to those who want to develop an independent research program—most academic neuropath openings will claim they want you to do independently-funded research, but beware of red flags like being asked to commit 50% or more of your time to clinical work “until you get a grant” (which probably won’t happen if you’re devoting that much time to clinical), or splitting your clinical time between neuropath and general surgical path.
4. What city (other than Lexington, KY of course) would you like a future American Association of Neuropathologists meeting to be held and why?
I think Salt Lake City would be a neat change of pace from the typical destinations. It’s fairly easy to fly to, it’s relatively inexpensive, the weather’s good in June, and the mountain scenery is gorgeous.
Tuesday, September 15, 2009
When you've exhausted your differential diagnoses for a nerve mass, Dr. Kleinschmidt-DeMasters is here to help
Reference: Kim DH, Murovic JA, Tiel RL, Moes G, Kline DG. A series of 146 peripheral non-neural sheath nerve tumors: 30-year experience at Louisiana State University Health Science Center. J Neurosurg. 2005;102:256-266.
Monday, September 14, 2009
An article entitled Fellowship Trends of Pathology Residents appears in the current issue of Archives of Pathology and Laboratory Medicine by Drs. Nikolaj Lagwinski and Jennifer L. Hunt. The following national data for 2006-2007 from the ACGME is provided in Table 5 of the article:
Number of Neuropathology Fellowship Programs: 35
Number of approved positions: 75
Number of positions filled: 39
Calculated fill rate (%): 52
Monday, September 7, 2009
Saturday, September 5, 2009
In an article entitled "Ependymoblastoma: Dear, Damned, Distracting Diagnosis, Farewell!" published online in Brain Pathology, authors Alexander R. Judkins (UPenn) and David W. Ellison (St. Jude's, Memphis) adapt a line from Alexander Pope's poem A Farewell to London (1715) for their title. Judkins and Ellison conclude the following: "We believe that ependymoblastoma as a diagnosis is neither precise nor specific and that it is time once and for all to retire this diagnosis from the lexicon of neuropathology." For now, the World Health Organization tumor classification sytem continues to recognize ependymoblastoma as a distinct nosologic entity. These neoplasms are often large, supratentorial, and usually connect to the ventricles. Although there is no definitive feature of ependymoblastoma, the ependymoblastomatous rosette is a histologic characteristic that has been used in making the diagnosis. A photomicrograph of such a rosette from the Judkins & Ellison article is shown. In this picture, epithelial membrane antigen (EMA) immunohistochemistry highlights the limiting lumenal membrane of rossette. (Update: Although published online in December '08, I have yet to see this article published in the print version of Brain Pathology.)
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