ObjectiveTo analyze the digital radiography(DR), CT, and MRI manifestations and clinical and pathologic features of skeleton Rosai-Dorfman disease(RDD) to improve the understanding of the disease.

MethodsTwo cases of skeleton RDD were analyzed retrospectively with a review of the literature on skeletal RDD.

ResultsTwo patients were examined before operation. One case had multiple lesions of long and flat bones on DR film, characterized by intramedullary and lytic lesion without periosteal reaction and cortical destruction or soft tissue involvement. Several lesions showed heterogeneous density. The other case had a singly lytic lesion of the cranial bone on CT image, characterized by a clear boundary and homogeneous density. T₁WI and T₂WI showed moderate signals, with a high signal on diffusion-weighted imaging and significantly enhanced on Gd-DTPA T₁WI. The adjacent scalp and the meninges were also affected.

ConclusionsRadiologically, most lesions are lytic and centrally located in the medullary cavity, infrequent with sclerotic borders or periosteal reaction. Cortical disruption or soft-tissue proliferation is rarely observed in the long bone, with a slight predilection in the cranial bone. The radiological features of skeletal RDD are not pathognomonic, so it must be differentiated with other diseases.