Uniform subclassification for patients with lymph nodes demonstrating features consistent with CD. Patients with lymph nodes demonstrating histology consistent with the CD spectrum (hypervascular/hyaline-vascular, plasmacytic, or mixed features) should be evaluated for number of regions of enlarged lymph nodes. If lymph node involvement is restricted to 1 site, the lesion most likely represents unicentric CD. If multiple sites are involved, patients should be evaluated for HHV-8, POEMS, and other infectious, malignant, and autoimmune disorders that can mimic iMCD. If these conditions are excluded, a diagnosis of iMCD should be considered. iMCD can be further subclassified into patients with iMCD with TAFRO syndrome (iMCD-TAFRO) and others whose subtype is not otherwise specified (iMCD-NOS). Adapted from Fajgenbaum et al.¹³