Langerhans cell histiocytosis is a disease that can damage tissue or cause lesions to form in one or more places in the body.

Langerhans cell histiocytosis (LCH) is a rare disease that begins in LCH cells (a type of dendritic cell which fights infection). Sometimes there are changes in LCH cells as they form. These changes may cause the LCH cells to grow and multiply quickly. This causes the LCH cells to build up in certain parts of the body, where they can damage tissue or form lesions.

LCH is not a disease of Langerhans cells that normally form in skin.

Scientists do not agree on whether LCH is a type of cancer or is a condition caused by a change in the immune system. LCH is mainly treated with anticancer drugs. Some of these drugs are also used to treat immune system conditions.

LCH may occur at any age, but is most common in young children. Treatment of LCH in childhood is different from treatment of LCH in adults. The treatments for LCH in children and adults are described in separate sections of this summary.

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with childhood Langerhans cell histiocytosis. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.

Family history and having a parent who was exposed to certain chemicals may increase the risk of LCH.

Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get the disease; not having risk factors doesn't mean that you will not get the disease. Talk with your doctor if you think you may be at risk. Risk factors for LCH may include the following:

• Having a parent who was exposed to certain chemicals such as benzene.
• Having infections as a newborn.
• Having a family history of thyroid disease.

The cause of LCH is not known.

The signs and symptoms of LCH depend on where it occurs in the body.

These and other symptoms may be caused by LCH. Other conditions may cause the same symptoms. Check with your doctor if you have any of the following problems:

Skin

In infants, signs and symptoms of LCH may include:

• Flaking of the scalp that may look like “cradle cap”.
• Raised, brown or purple spots anywhere on the body.

In children and adults, signs and symptoms of LCH may include:

• Flaking of the scalp that may look like dandruff.
• Raised, red or brown, crusted rash in the groin area, abdomen, back, or chest, that may be itchy.
• Bumps or ulcers on the scalp.
• Ulcers behind the ears, under the breasts, or in the groin area.

Mouth

Signs and symptoms of LCH may include:

• Swollen gums.
• Sores on the roof of the mouth, inside the cheeks, or on the tongue or lips.
• Having teeth that become uneven.
• Tooth loss.

Bone

Signs and symptoms of LCH may include:

• Swelling or a lump over a bone, such as the skull, ribs, spine, thigh bone, upper arm bone, elbow, or eye socket.
• Pain where there is swelling or a lump over a bone.

Lymph nodes and thymus

Signs and symptoms of LCH may include:

• Swollen lymph nodes.
• Trouble breathing.

Endocrine system (including the pituitary gland)

Signs and symptoms of LCH may include:

• Diabetes insipidus. This can cause a strong thirst and frequent urination.
• Slow growth.
• Late puberty.

Thyroid

Signs and symptoms of LCH may include:

• Swollen thyroid gland.
• Hypothyroidism. This can cause tiredness, lack of energy, being sensitive to cold, constipation, dry skin, thinning hair, memory problems, trouble concentrating, and depression. In infants, this can also cause a loss of appetite and choking on food. In children and teens, this can also cause behavior problems, weight gain, slow growth, and late puberty.
• Trouble breathing.

Central nervous system

Signs and symptoms of LCH may include:

• Loss of balance, uncoordinated body motions, and trouble walking.
• Trouble speaking.
• Changes in behavior.
• Memory problems.

Liver and spleen

Signs and symptoms of LCH may include:

• Swelling in the abdomen caused by a build up of extra fluid.
• Trouble breathing.
• Yellowing of the skin and whites of the eyes.
• Itching.
• Easy bruising or bleeding.
• Feeling very tired.

Lung

Signs and symptoms of LCH may include:

• Spontaneous pneumothorax (collapsed lung). This condition can cause chest pain or tightness, trouble breathing, feeling tired, and a bluish color to the skin.
• Trouble breathing, especially in adults who smoke.
• Dry cough.
• Chest pain.

Bone marrow

Signs and symptoms of LCH may include:

• Easy bruising or bleeding.
• Fever.
• Frequent infections.

Tests that examine the organs and body systems where LCH may occur are used to detect (find) and diagnose LCH.

The following tests and procedures may be used to detect (find) and diagnose LCH or conditions caused by LCH:

• Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.

• Neurological exam: A series of questions and tests to check the brain, spinal cord, and nerve function. The exam checks a person's mental status, coordination, and ability to walk normally, and how well the muscles, senses, and reflexes work. This may also be called a neuro exam or a neurologic exam.

• Complete blood count (CBC) with differential: A procedure in which a sample of blood is drawn and checked for the following:
  • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
  • The portion of the blood sample made up of red blood cells.
  • The number and type of white blood cells.
  • The number of red blood cells and platelets.

• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the body by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.

• Liver function test: A blood test to measure the blood levels of certain substances released by the liver. A high or low level of these substances can be a sign of disease in the liver.

• Urinalysis: A test to check the color of urine and its contents, such as sugar, protein, red blood cells, and white blood cells.

• Water deprivation test: A test to check how much urine is made and whether it becomes concentrated when little or no water is given. This test is used to diagnose diabetes insipidus, which may be caused by LCH.

• Bone marrow aspiration and biopsy: The removal of bone marrow, blood, and a small piece of bone by inserting a hollow needle into the hipbone. A pathologist views the bone marrow, blood, and bone under a microscope to look for signs of LCH.
  Enlarge
  

  Bone marrow aspiration and biopsy. After a small area of skin is numbed, a Jamshidi needle (a long, hollow needle) is inserted into the patient’s hip bone. Samples of blood, bone, and bone marrow are removed for examination under a microscope.

• Bone scan: A procedure to check if there are rapidly dividing cells in the bone. A very small amount of radioactive material is injected into a vein and travels through the bloodstream. The radioactive material collects in the bones and is detected by a scanner.
  Enlarge
  

  Bone scan. A small amount of radioactive material is injected into the patient's bloodstream and collects in abnormal cells in the bones. As the patient lies on a table that slides under the scanner, the radioactive material is detected and images are made on a computer screen or film.

• X-ray: An x-ray of the organs and bones inside the body. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body. Sometimes a skeletal survey is done. This is a procedure to x-ray all of the bones in the body.

• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
  Enlarge
  

  Computed tomography (CT) scan of the abdomen. The patient lies on a table that slides through the CT machine, which takes x-ray pictures of the inside of the body.

• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. A substance called gadolinium may be injected into a vein. The gadolinium collects around the LCH cells so that they show up brighter in the picture. This procedure is also called nuclear magnetic resonance imaging (NMRI).
  Enlarge
  

  Magnetic resonance imaging (MRI) of the abdomen. The patient lies on a table that slides into the MRI machine, which takes pictures of the inside of the body. The pad on the patient’s abdomen helps make the pictures clearer.

• PET scan (positron emission tomography scan): A procedure to find tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.
  Enlarge
  

  PET (positron emission tomography) scan. The patient lies on a table that slides through the PET machine. The head rest and white strap help the patient lie still. A small amount of radioactive glucose (sugar) is injected into the patient's vein, and a scanner makes a picture of where the glucose is being used in the body. Cancer cells show up brighter in the picture because they take up more glucose than normal cells do.

• Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later.

• Endoscopy: A procedure to look at organs and tissues inside the body to check for abnormal areas. An endoscope is inserted through an incision (cut) in the skin or opening in the body, such as the mouth. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of disease.

• Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for LCH cells. To diagnose LCH, a biopsy of bone lesions, skin, lymph nodes, or the liver may be done.

Certain factors affect prognosis (chance of recovery) and treatment options.

LCH in organs such as the skin, bones, lymph nodes, or pituitary gland usually gets better with treatment and is called "low- risk". LCH in the spleen, liver, bone marrow, or lung is harder to treat and is called "high-risk".

The prognosis (chance of recovery) and treatment options depend on the following:

• How old the patient is when diagnosed with LCH.
• How many body systems the disease affects.
• Whether the disease is found in the liver, spleen, lung, bone marrow, or certain bones in the skull.
• How quickly the disease responds to initial treatment.
• Whether the disease has just been diagnosed or has come back (recurred).

In infants up to one year of age, LCH may go away without treatment.