11/17/2020 In a paper published November 17th in the American Journal of Hematology, David Fajgenbaum, MD, MBA, MSc, and a team of international experts studied whether the National Comprehensive Cancer Network’s (NCCN’s) guidelines on idiopathic multicentric Castleman disease (iMCD) treatment were supported by data. Castleman disease lymph nodes can be subclassified as plasmacytic, hyaline vascular, hypervascular, or mixed based on the microscopic appearance, and the new NCCN guidelines recommend using this information to guide treatment decisions. This manuscript is significant because Dr. Fajgenbaum and team’s paper found that there is insufficient evidence to support using the microscopic appearance of lymph nodes to guide treatment decisions, and they hope that those guidelines with now be changed.