Langerhans Cell Histiocytosis

Normally, histiocytes help guard the body against infection. Histiocytosis occurs when large numbers of these immune cells grow out of control.

There are three major classes of histiocytosis, and each class represents a very different medical condition. LCH is the most common form of the condition and usually affects young children. The other two classes are non-Langerhans cell histiocytosis (non-LCH) and malignant histiocytosis. These occur much less frequently. One form of non-LCH is hemophagocytic lymphohistiocytosis (HLH) lymphohistiocytosis (HLH).

The cause of most cases of histiocytosis is unknown. It is thought that it may be an environmental trigger that results in an unusual reaction from the immune system. Some forms of histiocytosis are hereditary (passed down from parent to child). LCH has recently been shown to display genetic changes found in certain cancers.

LCH causes a wide range of symptoms which can include:

• Abdominal pain
• Bone pain
• Dizziness
• Ear drainage that continues for an extended time
• Eyes that appear to stick out
• Fever
• Frequent urination
• Headache
• Irritability
• Jaundice (yellowing of the skin and whites of the eyes)
• Limping
• Mental deterioration
• Rash
• Seizures
• Swollen lymph glands
• Thirst
• Vomiting
• Weight loss

LCH is sometimes associated with the following:

• Anemia (when histiocytosis is present in the bone marrow)
• Defects in bones or facial symmetry
• Delayed puberty (occurs when puberty has not started in boys by age 14 or in girls by age 13)
• Diabetes insipidus (inability of the kidneys to retain water, which results in excessive urination and thirst)
• Diffuse interstitial pulmonary fibrosis (hardening of tissue in the lungs that reduces the amount of oxygen available to the body)
• Failure to thrive (when a child does not grow as expected)
• Loss of teeth
• Lung problems that lead to lung failure
• Neurological problems such as tremors, poor coordination or memory loss
• Pituitary gland problems that lead to growth failure
• Scars on the skin or internal organs, such as the liver and lungs
• Short stature (when a child is much shorter than children of the same age and gender)

Diagnosis of Langerhans Cell Histiocytosis

A biopsy of tissue affected by LCH allows doctors to diagnose this disorder. A biopsy is a small bit of tissue taken from the tumor. It is examined under a microscope to determine if the cells of the tumor have the size, shape and specific proteins found in histiocytic tumors.

Doctors at Riley at IU Health may also have other tests done to determine the diagnosis of LCH. These tests include:

• Blood tests. A complete blood count (CBC) blood test checks the levels of red blood cells, white blood cells and clotting cells. Abnormal levels can be a sign of disease. Other blood tests check the levels of salts and proteins in the blood. Abnormal levels of these may also be a sign of disease.
• X-ray. Your child’s doctor may ask for X-rays of your child’s bones and lungs to see if there are any abnormalities.
• Bone scan. During a bone scan, a small amount of radioactive material is injected into a vein. This material collects in abnormal parts of the bones and can be detected with a scanner.
• Computed tomography (CT). A CT scan is a series of detailed pictures of the inside of the body.
• Magnetic resonance imaging (MRI). MRIs provide highly detailed pictures of the inside of the body. Injection of a chemical called gadolinium can help highlight affected areas.
• Positron emission tomography (PET) scan. In this test, a small amount of radioactive sugar is injected into a vein. The sugar makes metabolically active cells, such as cancer cells, show up brighter on the scanner.
• Ultrasound. An ultrasound uses sound waves that bounce off organs and tissue and make echoes. These echoes form a picture of the inside of the body.
• Urinalysis. This test reveals the amount of red blood cells, white blood cells, protein and sugar in the urine.
• Water deprivation test. A water deprivation test checks how much urine the kidneys make and if that urine becomes concentrated when your child does not drink. The doctor may ask for this test if he or she suspects diabetes insipidus.
• Upper endoscopy or colonoscopy. These procedures allow your child's doctor to look at the inside of the body by inserting a tube equipped with a small camera either through the mouth (upper endoscopy) or rectum (colonoscopy). Doctors often will take a biopsy at the same time.