VEXAS syndrome: A new mimicker of idiopathic multicentric Castleman disease.

• Only two cases of VEXAS with Castleman-like lymph node mimicking iMCD are reported in the literature. • VEXAS syndrome should be considered in the presence of iMCD suspicion, including patients with compatible histology. Idiopathic Multicentric Castleman Disease (iMCD) is a complex and poorly understood pathophysiological entity, which encompasses a variety of conditions and can mimic or be associated with autoimmune/autoinflammatory diseases, making it challenging to diagnose and treat. Vacuoles, Enzyme E1, X-linked, Autoinflammatory, Somatic (VEXAS) syndrome is an adult-onset autoinflammatory disorder associated with hematological abnormalities and caused by acquired somatic mutations in the ubiquitin-like modifier activating enzyme 1 gene (UBA1) which shares several common clinical and biological signs with iMCD. In this article, we report a patient with VEXAS syndrome initially presenting as iMCD, questioning the link between these two entities. We report here a patient initially presenting as iMCD, proved on lymph node histology, which turns out to have a mutation at the splice acceptor site of exon 3 of UBA1 exhibiting VEXAS syndrome with Castleman-like lymph node. This is only the second case of VEXAS syndrome presenting as iMCD. VEXAS syndrome should therefore be considered in the presence of iMCD suspicion, including in cases of compatible histology. [ABSTRACT FROM AUTHOR]