Waay back in 2008, when I was but an undifferentiated pathology resident, I decided it would be hepful to create a 2D map of primary CNS tumors since these are often best understood in terms of age, location and basic morphologic patterns. This was updated again in 2011, and again in 2018, and again in 2020 to fit with the WHO 4th edition revisions. Now, I bring you the most recent update to include WHO-5 revisions. Oer 50 entities with pertinent microscopic findings, immunohistochemistry and molecular findings.

It's important to consider how many new entities are being defined, in this era of high-throughput tumor sequencing and methylation based tumor classification schemes. Novel tumors with similar histologic and immunophenotypic profiles are separated using biologic characteristics that are only accessible with ancillary studies. Furthermore, the applicability of histologic "grading" is of questionable clinical utility in a number of entities, where the molecular signature trumps morphologic biologic behavior.

Lastly, given the need to be able to read the text within these small boxes, I would highly recommend you print this as a multipage poster. This can be done using free adobe reader software, under print > poster > 50% tile scale. The document is more readable. I have posted several versions of the map to suit your preference, including a "larger font" version that you can print on a single page and still (with some effort) read. My hope is that this helps demistify the crazy world of CNS tumors for learners and experienced pathologists alike.

- Chandra