Thursday, March 21, 2013

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.

Friday, March 15, 2013

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!

Thursday, March 14, 2013

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!