Board question/clinical pearl alert: Hairy Kidney Sign is an important indicator of Erdheim-Chester. Dr. @anisha_dua #RWCS24 @RheumNow @RWCSmtg - abnormal histiocytes now classified as malignancy - bone pain common presenting complaint - can see aorta, pleura, pericardium… https://t.co/XO5GXSNJZk https://t.co/gBn8Hii7F0