Rosai-Dorfman is a very rare condition with unknown etiology characterized by histiocyte-rich lymphadenopathy throughout the body. I had never encountered this disease process before my preceptorship on Thursday and was eager to learn a bit more in spite of its low prevalence.

The cervical lymph nodes are typically involved although literature references to axillary and mesenteric node involvement have also been made.. One of the histological hallmarks of Rosai-Dorfman is emperipolesis (cool medical word) aka “one cell living inside another.”

Thymus biopsy. Arrow indicates emperipolesis 1

Although a patient’s imaging and biopsies might look forboding, the NIH describes Rosai-Dorfman as a “self-limited and seldom life-threatening disease which commonly does not require therapy.” That’s reassuring. 🙂

So the next time I’m asked to list the differential for cervical lymphadenopathy, the common cold and Ebstein Barr virus are being shoved to the bottom of the list – it’s Rosai-Dorfman disease! This will promptly result in scolding by my residents and a refresher on how “common things are common” by my attending.

1. https://www.ajronline.org – PDF PET of Rosai-Dorfman Disease of the Thymus

Write A Comment