[Recent advances in TAFRO syndrome and Castleman disease]

TAFRO syndrome, first described in 2010, is an acronym for thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly. Due to its histopathological overlap with multicentric Castleman disease (MCD), some researchers consider TAFRO syndrome to be a subtype of idiopathic MCD (iMCD). However, the clinical features of TAFRO syndrome differ significantly from those of iMCD without TAFRO. Patients with TAFRO syndrome, regardless of iMCD histopathology, exhibit similar clinical characteristics and require prompt and accurate diagnosis and treatment. Although histopathological evaluation, including differential diagnosis, is essential, lymph node involvement is often minimal or absent in TAFRO syndrome. Castleman disease (CD) is clinically classified into unicentric CD (UCD) and MCD. Histopathologically, CD includes several variants: hyaline vascular, plasma cell, mixed, hypervascular, and plasmablastic. MCD is further classified etiologically into human herpesvirus-8 (HHV-8)-associated, HHV-8-unassociated (iMCD), and other types. iMCD is further subdivided into iMCD-TAFRO, iMCD with idiopathic plasmacytic lymphadenopathy (iMCD-IPL), and iMCD not otherwise specified (iMCD-NOS). Various other disorders may also present with iMCD- or TAFRO-like symptoms, complicating the differential diagnosis in borderline cases. Therefore, precise and disease-specific biomarkers must be established.