Sinus histiocytosis with massive lymphadenopathy

also known eponymously as Rosai-Dorfman disease

is a rare disease that is defined as a self-limiting proliferation of non-Langerhans histiocytes. The most common and typical presentation is painless bilateral cervical lymphadenopathy. Bone involvement in Rosai-Dorfman disease occurs in fewer than 10% of patients. In osseous Rosai-Dorfman disease

most patients suffer from a chronic course

and the cranial and facial bones as well as tibia are the most common sites. The clinical manifestations of the disease lack specificity

and the diagnosis is mainly based on routine pathological and immunohistochemical staining. Clinical presentation involves pain and swelling. On radiograph

typically

skeletal lesions are lytic and intramedullary

sometimes with surrounding sclerosis. The etiology of Rosai-Dorfman disease has been poorly understood so far. It has been hypothesized that Rosai-Dorfman disease may involve underlying host immune dysregulation

IgG4- related disease

various autoimmune disorders and gene mutation. Treatments primarily depend on specific locations of Rosai- Dorfman disease

including curettage or resection

steroids and chemotherapy. Since the clinical and radiologic manifestations of Rosai-Dorfman disease are often suggestive of malignancy

these patients might receive aggressive therapy. Whole-body PET/CT has proven to be a useful method for the management of Rosai-Dorfman disease

primarily for the staging

follow-up and evaluation of treatment results.