Langerhans Cell Histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disorder that primarily affects one in 200,000 children. A histiocyte is a form of white blood cell, which is found in every human body. Its job is to help destroy certain foreign materials and fight infection. The cause is unknown, but for some reason, patients with this disease have too many histiocytes (Langerhans cells). These cells accumulate in certain areas and cause problems. Langerhans cell histiocytosis has also been known as Histiocytosis-X , Eosinophilic granuloma, Hand-Schuller-Christian syndrome, and Letterer-Siwe disease.

A patient can have very limited involvement in only one part of the body, or involvement in many different sites. Usually the disease is more serious when several sites are affected and the patient is a young infant. Possible sites of involvement include:

• Skin (rash)
• Bone (single or multiple lesions)
• Lung, liver, and spleen (enlarged)
• Teeth and gums (loose or lost teeth, swollen gums)
• Ear (chronic infections or discharge)
• Eye (vision problems or bulging)
• Central nervous system (excessive thirst and urination = diabetes insipidus)
• General symptoms like fever, weakness, and failure to gain weight may be present.

A diagnosis of LCH is usually made following a biopsy and microscopic examination of the affected tissue. To determine the extent of the disease and subsequent treatment plan, several other tests may be done. These include blood tests, x-rays of the chest and bones (skeletal survey), and CT scans. Sometimes a biopsy is performed of the liver or bone marrow.

Treatment, if any, depends upon the individual patient. In some cases the disease will regress without any treatment at all. In others, limited surgery, small doses of radiation therapy or chemotherapy will be prescribed, depending on the extent of the disease. Treatment is planned after thorough evaluation of the patient to determine the extent of involvement. The goal of an overall treatment plan is to use as little treatment as possible to keep the disease under control. Although this disease is not considered to be a cancer, cancer treatments have been used in patients with histiocytosis. Consequently, hematologists and oncologists, who treat cancer, also treat children with Langerhans cell histiocytosis. Radiation therapy, if used, is given in much lower doses than that which cancer patients receive.

The vast majority of patients will survive the disease. Some may develop lifelong chronic problems, while others remain symptom free. In some cases the disease is fatal. Usually these are very young infants who have a rapid downhill course and do not respond to any known treatment. Whether or not the disease responds to treatment will often depend on the extent of organ involvement.