A sizable shift in CNS tumor classification
November 2021—Much has changed since the last WHO classification of central nervous system tumors was published five years ago. Case in point: When the group of authors met in Utrecht, the Netherlands, in late 2019, everyone anticipated two more WHO meetings in Europe to work further on the 2021 classification. Arie Perry, MD, a coauthor on both classifications, says the group photo was cheery. “Everybody was smiling.” The later trips to Europe were canceled because of the pandemic and the group met instead by Zoom. “Now everybody looked grumpy,” he says of a screen shot. Fortunately, “We got everything done, even if it wasn’t quite as pleasant,” says Dr. Perry, professor of pathology and neurological surgery, Department of Pathology, Division of Neuropathology, University of California, San Francisco. The result is the latest WHO classification, which offers dramatic changes of its own. “I’m really excited about the new WHO,” he says. “At first it takes a little getting used to”—like, say, a face mask—“but I think it’s another major advance, just like we had last time.”