Medical School Pathology: Neoplasms & Familial Tumor Syndromes of the Central Nervous System

[@salomonscheepers6331]

Thanks, great presentation!

[@moshesadofsky9429]

It wasn't clear to me, so I looked it up! When Dr. Deyrup shows an IHC (immunohistochemistry) stained slide and says "this confirms the diagnosis of mutant IDH-1", what you are seeing is the brown staining pattern that represents an enzyme-linked indicator when an antibody binds a target protein. And the key fact here is that the antibody being used has been carefully chosen to bind to certain particular mutant forms of the IDH-1 protein. So binding (brown color) indicates that the mutant protein is present. Normal cells would not bind this antibody. This lecture is beautifully presented, and I think very appropriate for later students and residents. For beginning students, it is worth appreciating the morphologic patterns, and the increasing use of genetic data in defining the tumor. It is also worth dwelling a bit on the use of the word Tumor. It is not always malignant. Literally it is a growth. (unexpected, undesired, maybe dangerous). But if it is invasive, then it qualifies as a Malignant tumor. That's what we mean by cancer. Sometimes we can't tell.

[@PathologyCentral]

Thank you for clarifying the IHC issue, Dr. Sadofsky. This information, while good for later students and residents, reflects the updated material in the 11th edition of Robbins & Kumar Basic Pathology to include the latest WHO classification of tumors!