How do you calculate a brain tumor's MIB-1 index?

Elizabeth J. Cochran, MD

I was recently contacted by the affable Elizabeth Cochran, MD  asking if I would post a query regarding MIB-1 counts on brain tumors. Does anyone know if there is a standardized approach to this?  Please tell us your approach to MIB-1 quantification in the comment section. Dr. Cochran takes an approach based on an article she had read in Human Pathology some time ago, summarized as follows:

1. Examine control section stained with MIB-1 antibody to confirm that the stain worked.

2. Survey the slide of the case to be counted to find the area(s) that have the most stained nuclei.

3. Put reticule in right eyepiece of microscope.

4. Place the area identified in #2 under the reticule at 40x power.

5. Using the hand held counter, count all the immunoreactive nuclei within the entire grid.

6. Count all nuclei that touch the right and bottom outer border of the grid, but NOT the nuclei that touch the upper and left borders.

7. Record this number in the lab book.

8. Count all nuclei present within one vertical column of the grid.  This column should be randomly chosen.

9. Record this number in the lab book.

10. Count all nuclei present within one horizontal column of the grid.  Again this column should be randomly chosen, and recorded in the lab book.

11. Again, be sure to count all nuclei that touch the right and bottom outer border of the grid, but NOT the nuclei that touch the upper and left borders

12. Repeat this procedure for at least two more high power fields on the section that contains the most numerous immunostained nuclei and record all values in the lab book.

 13. Calculate the MIB-1 proliferative index as follows:

                a. For each of the fields counted: Add all of the nuclei counted in each row and column from each field and multiple by five.  Divide the number of the immunostained nuclei counted in that field by the calculated sum of all of the nuclei in that field.

                b. The total number of all cells counted in all fields should be > 1000.  If it is substantially less than 1000, count another field, as described above.

                c. Calculate the average of the three fields and  record the proliferative index in the lab book.

An oddball sellar region mass

In the last post, it was noted that Dr. Peter Burger presented a series of sellar region "oddball lesions" at the recent USCAP meeting. The esteemed Dr. Mark Cohen was good enough to provide photographs (above) of one particular lesion that was discussed at the meeting: an osteolipoma of the tuber cinereum. Thank you, Dr. Cohen!

Dr. Thomasina Bailey reviews pituitary session at recent USCAP meeting

A guest post from Thomasina Bailey, MD:

 I spent Saturday night, March 9,  up late in Baltimore at the AANP session at USCAP.  The talks focused on sellar lesions. The panel consisted of  Drs. Lopez, Kleinschmidt-DeMasters, and Burger.  Dr. Lopez  from UVA gave a really great overview of sellar lesions focusing in on pituitary adenomas.  She discussed the things that are clinically significant in the work-up of pituitary adenomas along with the controversies over atypical adenomas and carcinomas of the pituitary.  At the end of her talk, she listed her own WHO classification of pituitary adenomas giving a comparison to meningioma WHO grading.

The next lecture was given by Dr. Kleinschmidt-DeMasters of University of Colorado on What’s New in Inflammatory Pituitary Lesions, Pituicytomas, Spindle Cell Oncocytomas,  and Craniopharyngiomas. During this hour numerous cases were reviewed. Of particular interest was the clinical pathological correlation of pharmacological treatment and the development of hypophysitis.  As she referenced articles and cases she called out audience members who were their authors. During the course of the talks there was a lot of audience interaction when comparing and contrasting use of certain antibodies.

The icing on the cake was Dr. Burger's talk on oddball lesions of the sellar region. He started off the talk by noting that no one will probably ever see in their practices the entities he was about to share. He called on the audience including some of his former fellows for their thoughts. The last case was of special interest because he sited a case report from 1855.  He talked about going to Welch Library to find the journal and then went off on an enjoyable tangent about Dr. Welch being the first pathology chair at Hopkins. Spending a Saturday night at a science talk was super geeky, but I love neuropathology and the pathology history lesson was a bonus.  It was neat to think about all the really great neuropathologists sitting in the audience as well as at the podium. I just wish Dr. Perry had sung a  little bit in the beginning!

Review by Dr. Mark Cohen of "Neuropathology: A Volume in the High Yield Pathology Series", edited by Yachnis and Rivera-Zengotita

Mark L. Cohen, MD

I am honored to present a guest post by the inimitable Dr. Mark Cohen of the illustrious Case Western Reserve University. Dr. Cohen not only reviews a great new neuropathology textbook, but illustrates yet again why he is widely known as the Maxwell Smart of Neuropathology.

(Not really) Full disclosure

Self-annihilating conflicts of interest, as follows:

1. Long-standing professional relationship with unbridled admiration for lead editor Tony Yachnis, both as a person and as a pathologist (he's not the Moderator of the world-famous Diagnostic Slides Session of the American Association of Neuropathologists, as well as their President-Elect, for nothing).
2. I have contributed to several publications that compete within the same niche, and from which I have amassed a small fortune (recently enabling me to purchase new windshield wipers for my ‘99 Corolla).

Several weeks ago, I received the following teaching evaluation from an anonymous medical student: "One of the worst lecturers that I had the misfortune of experiencing in medical school. Powerpoints were poorly constructed in terms of high yield content...”. So, when our host Dr. Moore blogged about the impending publication of Neuropathology: A Volume in the High Yield Pathology Series, I sprinted to my laptop to pre-order a copy.

Anthony T. Yachnis, MD, MS

The book arrived safely last night (albeit buried in several inches of snow), and I was not disappointed. Best described as Text-Atlas, it weighs in at 351 pages, which is roughly half that of both Perry & Brat’s Practical Surgical Neuropathology and Prayson’s Neuropathology, second edition. In addition, it represents something of a revolutionary approach in that it was primarily written by trainees in pathology, neuropathology, dermatopathology, hematopathology and neurosurgery. This team-based approach (a testament to Captain Tony’s coaching skills) has produced a neuropathology text “of the people, by the people, and for the people”, as well as resulting in a textbook which is remarkably up to date (including such topics as Natalizumab-related PML). In addition to an introduction to basic neuropathological reactions, subjects covered include developmental disorders (both malformative and acquired), cerebrovascular disorders, trauma, brain tumors, infectious diseases, neurodegenerative disorders, demyelinating diseases, toxic/metabolic disorders, and neuromuscular disorders. For a book of this size, the scope of the topics covered is remarkably comprehensive, and they are extensively, if not exhaustively, illustrated. The pictures, especially the gross photographs, are of uniformly high quality (which appears to be maintained in the on-line version, unlike another high-profile textbook I reviewed a few years ago). In addition to the beautifully photographed gross specimens, pictures include histochemistry, immunohistochemistry, and neuroimaging, as appropriate. The vast majority of the photographs are reproduced at 3.25 x 2.5 inches, which is more than adequate to appreciate the features described in the figure legends. With rare exceptions, arrows are not included within the photomicrographs (which I feel is appropriate, but has gotten me in trouble with certain journals, publishers, and students). As is the practice within this series of textbooks, as well as in many other currently published pathology books, the text is entirely bulleted (a practice which I personally dislike, but which is executed quite well here). Another feature that the reader should be aware of is that (no doubt as part of the philosophy of “high-yield pathology”) there are no references.

Marie Rivera-Zengotita, MD

As an academic neuropathologist, do I have criticisms? (Do bears sh...?). Besides minor quibbles with organization (I probably would have included Natilizumab-associated PML within the Infections section rather than as part of multiple sclerosis) and such Talmudic issues as whether brain invasive meningiomas are truly atypical or not really atypical, but still WHO Grade II, I think that the improvements that I would suggest are largely outside the purview of the authors and editors. Specifically, the titling typography and design layout is nothing short of hideous, and, although the pictures are of adequate size, the presence of many nearly blank pages certainly makes me wish that those spaces had been filled by larger format photographs. In addition, a few of the topics are presented sans photographs, which detracts somewhat from the flow of the textbook (although the authors had the good sense of not trying to illustrate mixed oligoastrocytomas). All in all, however, I think that the book succeeds in its aspirations of presenting "high yield neuropathology".

The editors hope that the volume will be useful for trainees in pathology, neurology, neurosurgery, neuroradiology, neuro-oncology and related fields; as well as being a practical reference for practicing pathologists -- including neuropathologists requiring quick access to the field. As I was reading through the text, I kept this in mind, and triaged these groups as follows:

1. Neurology and neurosurgery residents should run, not walk, to order a copy, as Board examinations are near at hand, and this book provides a perfect study guide for preparation. Neuropathology fellows should also obtain a copy for studying, although at this moment they have time to walk to their laptops or bookstore.
2. Neuroradiologists and anatomic pathologists should obtain a copy to keep as a quick reference
3. Neuro-oncologists will probably gravitate towards more specialized textbooks (such as the recent addition to the Diagnostic Pathology series edited by PCB et al.)
4. As far as practicing neuropathologists go, I think we all need a copy as we generally find ourselves in one of two situations:
1. A private practice or group setting without instantaneous access to literature databases. For this group, I think the book fulfills its goal as a quick access to diseases with which we may have become unacquainted during our time in practice.
2. A large academic medical center with broadband access to literature databases. In this position, our quick access will generally be on-line. On the other hand, we should all have a copy to lend to clinical rotators as an expression of our great goodwill. (Another minor weakness of the book is that there is no RFID device by which we can geolocate our books once they have left our offices. On the other hand, the included on-line access assures that even as our copies disappear, we will still have access from our computers).

Unfortunately, while I feel this book will definitely help to guide me in the revision of my medical student lectures, it is by itself not appropriate for medical student study. To paraphrase Jack Nicholson as Col Nathan R. Jessup, USMC in A Few Good Men: You want high yield? You can’t handle high-yield!

Luckily, for those who can handle the truth, Neuropathology: A Volume in the High Yield Pathology Series will provide a valuable and lasting resource.

A Primer on Perinatal Telencephalic Leukoencephalopathy

In my last post, it was correctly pointed out by two astute readers that the Netter figure demonstrating brain malformations included an entity which is NOT a brain malformation: perinatal telencephalic leukoencephalopathy (PTL). PTL results from a perinatal hypoxic insult and is not a malformation per se, as the term "malformation" should really be reserved for anatomic abnormalities resulting from developmental defects. The cerebral white matter in the fetus and neonate is particularly susceptible to injury as it is metabolically highly active. Ischemia of the germinal matrix, subependymal region, and periventricular white matter can lead to periventricular leukomalacia that may even calcify and result in periventricular mineralization (1). At its most extreme, PTL may take the form of hemispheric multicystic leukomalacia in which the cerebral hemispheric white matter is replaced by multiloculated cysts separated by strands of fibroglial tissue.(2)

References:
1. Fuller, Gregory N. and Goodman, J. Clay. Practical Review of Neuropathology. Lippincott 2001. Page 315.
2. Haberland, Catherine. Clinical Neuropathology: Text and Atlas. Demos Publishing 2007. Page 303.

Brain Malformations

Best Post of August 2012: A case of renal cell carcinoma metastatic to a meningioma

The next in our "Best of the Month" series is from August 9, 2012:

A 74-year-old woman with a history of a seizure disorder had been followed for several years with a stable and unsymptomatic left parasagittal dural-based brain tumor presumed to be a benign meningioma. Recently, though, the lesion increased in size and hemorrhaged, leaving her significantly paretic on the right side. Neurosurgery thereupon performed a craniotomy for tumor removal. Intraoperative frozen section diagnosis was meningioma. But, upon receipt of the permanent sections, I was impressed by the staghorn vessels at low power and hemangiopericytoma immediately came to mind.

Staghorn vessels prominent in region below dot marks

Psammoma body consistent with original impression that this was simply a meningioma

Whirled architecture consistent with meningioma

I was obviously dealing with a meningioma, but something else was going on in that area featuring the staghorn vessels. This region exhibited a different histomorphology:

Clear cells

High-power view of clear cell portion of specimen

This dual morphology puzzled me. I then discovered that back in 2003 the patient had undergone a radical nephrectomy for renal cell carcinoma. Surgical margins of the nephrectomy specimen were free of tumor. I retrieved the 2003 nephrectomy specimen, which looked quite similar to the clear cell portion of the brain tumor:

Nephrectomy specimen from 2003 showing renal cell carcinoma, clear cell type

I thereupon went back to the brain tumor specimen and did some immunohistochemical stains, including RCC for suspected renal cell carcinoma metastasis:

Positive RCC Immunohistochemistry

I had a case of renal cell carcinoma metastatic to a meningioma! Such a case had been reported in the literature before:

Han, HS, et al. Metastatic renal cell carcinoma in a meningioma: a case report. J Korean Med Sci. 2000 October 15 (5):593-597.

Here's case number two!

Follow-up: The patient received radiation to the tumor bed and is recovering.

Yachnis and Rivera-Zengotita team up to bring us some high-yield neuropathology

Who doesn't love the feel of a brand new textbook in your hands, and that first subtle crack of the binder as you open the cover releasing the synthetic fragrance of smooth new paper? We will get to re-live that feeling when Dr. Anthony Yachnis' Neuropathology: A Volume in the High-Yield Pathology Series is released. The book has a copyright year of 2014, so we may have to wait a while before it is released. But, if the good Dr. Yachnis is the principal author, it will surely be worth the wait. In his preface, written with co-author Dr. Marie L Rivera-Zengotita, Dr. Yachnis writes: "Our intent in producing this volume is not to replace several other outstanding comprehensive textbooks in the field but rather to provide quick reference via bulleted summaries of key facts that are supported by multiple representative photographs on topics of interest in the major areas of neuropathology. We have attempted to provide rapid access to a range of nervous system disorders for trainees and practitioners.... It should be a handy practical reference for practicing pathologists, including neuropathologists requiring quick access to the field" This book does not just cover tumors, but also malformations, cerebrovascular disorders, trauma, infectious disease, demyelinating disease, neurodegenerative disorders, toxic-metabolic disease, peripheral nerve disease, and muscle disease.  I think I can speak for the entire neuropathology community, Dr. Yachnis, in saying that we eagerly look forward to getting our hands on this book.

The biggest Alzheimer Disease discovery in 2012

Kári Stefánsson

Perhaps the biggest discovery in the Alzheimer research world last year was the identification of a mutation in APP that significantly decreases its cleavage by β-secretase, leading to 40% less production of amyloidogenic peptides in vitro. The researchers found the mutation (A673T) in the APP gene protects against Alzheimer’s disease and cognitive decline in the elderly without Alzheimer’s disease.

Future drugs that can recreate this Aβ-reducing effect “should perhaps be given not only to people at risk of Alzheimer’s but to all elderly people,” says Kári Stefánsson, senior investigator of the study, which came out of Iceland and appears online in Nature.

Best Post of July 2012: "Chasing The Dragon": A Cause of Toxic Spongiform Leukoencephalopathy

The next in our "Best of the Month" series comes from July 10, 2012:

My favorite case from the 2012 AANP Diagnostic Slide Session in Chicago last month featured an autopsy slide from the brain of a 25-year-old man with a history of polysubstance abuse found unresponsive at a New Year's Eve party. Toxicology screening was positive for methadone, lorazepam, and cocaine. The patient died after three weeks in the intensive care unit. Attendees were provided glass slides in advance of the session demonstrating the following findings:

Low Power: Marked white matter pallor

High Power: White matter virtually replaced by lipidized macrophages

Presenter Joshua Menke, MD of The Mayo Clinic (Rochester, MN) revealed that white matter damage was diffuse, including infratentorial structures. The subcortical U-fibers were relatively spared and myelin was disproportionately affected as compared to axons, as demonstrated in these photomicrographs from Dr. Menke's presentation:

LFB stain on left and neurofilament stain on right

Discussants included Drs. Tessa Hedley-Whyte, Craig Horbinski, Mark Cohen, and others. Before the diagnosis was revealed, Dr. Horbinski stated that he thought Delayed Hypoxic Leukoencephalopathy might be the best fit for this case. Dr. Cohen pointed out that Delayed Hypoxic Leukoencephalopathy tends spare the infratentorial regions, while the white matter damage is more diffusely distributed in toxic leukoencephalopathy. This case was ultimately revealed to be that of Toxic Spongiform Leukoencephalopathy.

Toxic leukoencephalopathy can be caused by a range of insults including radiation, chemotherapy, and drugs of abuse. Among the drugs of abuse that have been shown to cause toxic leukoencephalopathy are toluene, ethanol, cocaine, 3,4-methylenedioxy-methamphetamine, intravenous heroin, inhaled heroin pyrolysate, and psilocybin (Ref: Filley & Kleinschmidt-DeMasters NEJM 2001). Toxic spongiform leukoencephalopathy is a clinicopathologic entity first associated with the inhalation of pyrolysate heroin vapors, a practice which had its origins in Hong Kong in the 1950's and which came to be known colloquially as "chasing the dragon". Users typically "chase the dragon" by placing heroin on a creased piece of tin foil over a flame. As the drug sublimates, the user inhales the fumes. The pathophysiology of this form of leukoencephalopathy has not been clearly elucidated, but is thought to be related to a direct toxic effect of heroin on oligodendrocytes.

Posted by Brian E. Moore, MD at 12:48 PM

Best Post of June 2012: Neuropathologists party hard at AANP Annual Reception

The next in our "Best of the Month" series comes from June 22, 2012 and recalls fond memories of an excellent annual meeting of the American Association of Neuropathologists this past summer in Chicago:

L to R: Drs. Heather Sumner and T. David Bourne

Drs. Mark Cohen, T. David Bourne, and Mahtab Tehrani

L to R: Drs. Edward Stopa, William Taylor, and Qian Wu