“…4 The prevalence is estimated at 1:200 000, affecting children and young adults most commonly, with an unclear pathogenesis although recent evidence has suggested a viral stimulus, including Epstein Barr virus, HIV, or cytomegalovirus (CMV). 8 Classically, RDD presents nodally, with 43% presenting extranodally, and may present over months to years like other forms of non-LCH. 4 Patients typically have bilateral, massive, painless cervical lymphadenopathy, multisystem involvement, including the skin, bone, and gastrointestine (GI), although CNS involvement is less common.…”