Osseous Rosai–Dorfman Disease Presenting as a Solitary Lesion of the Distal Radius

Rosai–Dorfman disease, also known as sinus histiocytosis with massive lymphadenopathy, is a rare entity in which bone involvement occurs in less than 5% to 10% of patients and skeletal cases are usually multifocal. Extranodal solitary lesions of bone without nodal involvement or additional clinical manifestations are exceedingly rare. We present the clinical course and management of a 34-year-old African American woman who presented with the disease as a solitary lesion of the distal radius.