06/02/2025 Important insight for Castleman disease patients: Idiopathic multicentric Castleman disease (iMCD) is a rare lymphoproliferative disorder classified into three recognized clinical subtypes: idiopathic plasmacytic lymphadenopathy (IPL), TAFRO, and NOS. Although clinical criteria are available for subtyping, diagnostically challenging cases with overlapping histopathological features highlight the need for an improved classification system. Integrating clinical and histopathological findings the authors aimed to develop an objective histopathological subtyping system for iMCD that closely correlates with the clinical subtypes. By evaluating excisional lymph node specimens for five key histopathological parameters and using hierarchical clustering, the study visualized subgroups and developed a machine learning-based decision tree to differentiate the clinical subtypes and validated it in an external cohort of patients with iMCD. The developed histopathological classification system closely aligns with the clinical subtypes, offering a more precise approach to iMCD subtyping and may enhance diagnostic accuracy, guide clinical decision-making for predicting treatment response in challenging cases, and improve patient selection for future research.
