Fulminant relapse of idiopathic multicentric Castleman disease with TAFRO-like phenotype in intensive care

Idiopathic multicentric Castleman disease (iMCD) is a rare lymphoproliferative disorder characterized by disproportionate immune activation driven primarily by interleukin-6 (IL-6). Some relapses may adopt a TAFRO-like phenotype, associated with greater severity and accelerated progression to multiorgan failure. We describe a 73-year-old male patient with a history of iMCD who was admitted for jaundice, abdominal pain, and systemic deterioration. The evolution was rapidly progressive, with severe thrombocytopenia, acute renal failure, anasarca, and vasoplegic shock, without evidence of infection or autoimmune disease. Inflammatory markers showed markedly elevated IL-6 (136 pg/mL). Given the impossibility of accessing siltuximab, pulses of methylprednisolone were administered, without managing to revert the progression to multiorgan failure, resulting in the patient's death. The case illustrates the diagnostic difficulty of fulminant iMCD, whose initial presentation can simulate infectious or hepatobiliary conditions. The identification of the TAFRO-like phenotype is crucial, given its more aggressive clinical behavior and high mortality. This report highlights the importance of early recognition, the use of biomarkers such as IL-6, and the availability of targeted biological therapies. iMCD with a TAFRO-like phenotype represents a significant therapeutic challenge, especially in limited-resource settings. Early clinical suspicion and access to anti-IL-6 treatments are fundamental to improving outcomes.