Rosai-Dorfman disease in neuroradiology: Imaging findings in a series of 10 patients

OBJECTIVE. Rosai-Dorfman disease is a rare disorder characterized histologically by lymphatic sinus dilatation due to histiocyte proliferation. Our goal was to describe the CT, MRI, and ¹⁸F-FDG (FDG) PET findings in a series of patients with this diagnosis. MATERIALS AND METHODS. We retrospectively reviewed the imaging studies of 10 patients with pathologically confirmed Rosai-Dorfman disease who were treated in our institution between January 2004 and December 2007. RESULTS. We found the following areas of general involvement: three intracranial, seven head and neck, and three spinal, with some patients having more than one site. Specific sites of involvement included the following: intracranial meninges, n = 2; pituitary, n = 2; lacrimal gland, n = 1; paranasal sinus, n = 3; neck lymph nodes, n = 6; salivary gland, n = 3; tonsil, n = 1; skin, n = 1; spinal meninges, n = 2; vertebral body, n = 1; and thymus, n = 1. The MRI characteristics of the involved areas were generally T1 isointense, T2 isointense, diffusion isointense to gray matter, and intensely enhancing with gadolinium chelate contrast agents. CT images generally showed the lesions were hyperdense to gray matter and intensely enhancing. FDG PET showed variable uptake, with nodal and lacrimal disease generally being FDG avid and other sites not. CONCLUSION. Rosai-Dorfman disease has a protean imaging appearance but most frequently presents as neck lymphadenopathy. The disease is frequently multifocal, and a diagnosis in one area should prompt suspicion that other sites may be involved also.