Histiocytosis X Or Langerhans Cell Histiocytosis

Histiocytosis X is a term that has been used to describe a group of different types of illnesses that share a common origin. Until recently, these diseases were put into one of these categories:

  1. Eosinophilic granuloma was thought to be the most benign or mild form of histiocytosis X, characterized by a lesion of the bone, which can result in pain and swelling.
  2. Hand-Schüller-Christian disease usually refers to children with bone lesions often in the skull, prominent eyes, and frequent urination.
  3. Letterer-Siwe disease refers to a generalized disease that has a very aggressive, often fatal ending. Organs that may be involved include bone, lungs, skin, liver, spleen, and bone marrow. This type is usually seen in children less than 2 years old.

Now due to a better understanding about this disease, it is called Langerhans cell histiocytosis (LCH). LCH is a disease in which the Langerhans cells (called histiocytes) are increased in number and invade various tissues of the body. Histiocytes are cells normally found throughout the body and are most often found in the spleen, lung, liver, bone marrow. They are part of the reticuloendothelial system, which filters germs to prevent infections.

The trigger for the increase of Langerhans cells and their invasion is not known. Although more than one case has occurred in the same family, there is no clear evidence this disease is inherited.

Symptoms of LCH vary widely from a benign or mild form to a very aggressive, even fatal disease. Symptoms can develop at any age, but it is more common in children than adults. The most severe cases tend to occur in children under two years of age.

Symptoms depend on the organs of the body affected. Bones are a common site, occurring as a single lesion or many lesions. The lesions of the bones are usually found because of pain and swelling in the affected areas including the skull, femur in the leg, ribs, pelvis, vertebrae, and jaw.

The skin and scalp may also be involved. Skin lesions may include small sacs or blisters containing pus, small reddish elevations or bumps on the skin, scaly / greasy rashes, and purplish-red spots or bleeding under the skin. Swelling of the gums, early eruption of the teeth, and loss of teeth may occur. In addition, there may be draining from the ears.

When the hypothalamic / pituitary area of the brain is affected, diabetes insipidus may occur. The pituitary is located at the base of the brain. It produces a hormone called vasopressin that helps the body save water. When a mass of histiocytes gets in the way, hormone production is reduced or stopped. When this happens, the affected person is thirsty and has increased urination. Involvement of this area may also cause growth failure and thyroid problems.

LCH may also affect the lungs, causing breathing problems due to the disease or from an infection. The bone marrow is affected when the histiocytes multiply in the marrow and crowd out normal red cells, white cells, and platelets. A decrease in these cells may cause anemia and fatigue due to low red blood cells, increased infections due to low numbers of white blood cells, and the tendency to bruise easily and/or petechiae due to low numbers of platelets.

Diagnosis of LCH requires a biopsy or sample of the affected tissue or bone.

The treatment for LCH is varied and depends on the degree and extent of disease involvement in the child's body. Localized lesions, those lesions found in one general area, may require no treatment. If treatment is necessary, it may range from surgery or low-dose radiotherapy or chemotherapy.

The outcome of LCH is extremely variable. The two main factors which influence a child's prognosis appear to be age at the time of diagnosis, and how many organs are involved.

Children younger than 2 years at the time of diagnosis have a higher death rate than do older children.

Furthermore, the presence of major organ problems (liver, lung, bone marrow) has been shown to be an indicator of poor outcome. The involvement of multiple organ systems is also a poor prognostic sign.

Children with poor prognosis make up less than 15 percent of LCH cases. Children with localized lesions usually respond very well to treatment. However, it is not uncommon for children to develop second or third lesions requiring further treatment.

Eventually LCH runs its course and no further disease occurs.

For additional information on this topic, contact us, immunodeficiencies@cchmc.org.

Last Updated 12/2014