Sinus Histiocytosis with Massive Lymphadenopathy (SHML)
Rosai-Dorfman disease (RD), also known as sinus histiocytosis with massive lymphadenopathy (SHML), is a rare histiocytic disorder which involves the over-production of a type of white blood cell called non Langerhans sinus histiocyte. These cells then accumulate, most often in the lymph nodes, but may occur in other areas of the body and can lead to organ damage. The reason that these cells over-produce is not known, although many possibilities have been considered, including viral, bacterial, infection, environmental, and genetic causes.
In 1969, two pathologists, Juan Rosai and Ronald Dorfman, reported a distinct histiocytic disorder in several patients with massive enlargement of the lymph nodes, as well as other symptoms. They named this condition sinus histiocytosis with massive lymphadenopathy, and the name has since come to be known as Rosai-Dorfman disease.
The true number of RD cases is not known, although it does occur worldwide and seems to affect equal numbers of males and females. It is most commonly seen in the first 10 years of life, but it also occurs in adult patients.
Because this disease is so rare, no large studies have been performed, and there is no established, widely-accepted treatment. However, RD is usually not life-threatening, and many patients do not require treatment.
The Histiocytosis Association continues to work closely with an international group of physicians, known as the Histiocyte Society, who are dedicated to studying the histiocytic disorders. Through their combined efforts, awareness about the disease has increased, more research has been undertaken, and progress has been made in the understanding of this disease.
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