Osseous Rosai-Dorfman disease of tibia in children: A case report.

Background: Rosai-Dorfman disease (RDD), or sinus histiocytosis with massive lymphadenopathy, is a benign histiocytic disorder. Extranodal involvement is common, occurring in > 40% of patients, but bone involvement occurs in < 10% of cases. In addition, primary bone RDD is extremely rare. The majority of patients are adolescents and young adults, and the mean age at onset is 20-years-old.

Case Summary: We report an 8-year-old Chinese girl who presented to our hospital with an insidious onset of swelling and pain in the middle shaft of her right tibia for 4 mo. We performed total surgical resection of the right tibia lesion and allograft transplantation. A good prognosis was confirmed at the 6 mo follow-up. Pain and swelling symptoms were totally relieved, range of motion of her right knee and ankle returned to normal, and there was no clinical evidence of lesion recurrence at last follow up. Our case is the second reported case of osseous RDD without lymphadenopathy in the shaft of the tibia of a child.

Conclusion: Extranodal RDD is a rare disease and can be misdiagnosed easily. Lesion resection and allograft transplantation are an option to treat extranodal RDD in children with good short term result. Pediatric orthopedist should be aware of this rare disease, especially extranodal involvement.