What is histiocytosis?
Histiocytosis is an uncommon blood disease that occurs only once in every 200,000 births annually in the United States. Patients with histiocytosis develop an excessive number of white blood cells called “histiocytes.” Clumps of histiocytes can attack organs, including the lungs, ears, eyes, liver or the central nervous system. It is often treated with chemotherapy and radiation, even though it is not a form of cancer.