Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) presenting with skeletal lesions

A 2-year-old child presenting with bone pain and bone lesions was found to have sinus histiocytosis with massive lymphadenopathy (SHML). SHML presenting with skeletal symptoms is unusual. Management has been conservative and the child has been symptom free for 30 months, although the bone lesions have not completely regressed.