Langerhan's Cell Histiocytosis (LCH)

Overview

Langerhan's Cell Histiocytosis (LCH) is a rare disorder that occurs in about one in 200,000 children and adults each year. The disease causes an abnormally high level of histiocyte cells, which are produced in bone marrow. Histiocyte cells help fight bacteria and parasites and help with the production of antibodies.

Ordinarily, histiocyte cells are found in the skin, liver, lung, stomach, lymphatic glands, spleen, bones and parts of the brain. In histiocytosis, these cells reproduce excessively. Although the disease technically is not cancer, it behaves like cancer in its most serious form and is treated by cancer specialists. Treatments include medication, chemotherapy and sometimes radiation.

The disease also is known as Histiocytosis-X, Eosinophilic granuloma, Hand-Schuller-Christian syndrome and Letterer-Siwe disease.

Most cases of histiocytosis occur in children from birth to age 15, with the incidence peaking between 5 to 10 years of age. In children, 80 percent of the cases affect the bones. For example, the skull often is affected, developing a "punched-out" appearance that can be detected in a bone X-ray.

Children over 5 years old often experience only bone involvement, though younger children may be affected in many parts of the body simultaneously. If only one organ is affected, less intense treatment is required.

Other rare histiocytic diseases that affect children include hemophagocytic lymphohistiocytosis and familial lymphohistiocytosis, both which may be triggered by viral infections. Malignant histiocytosis is a rare form of leukemia in children.

Signs & symptoms

Among children, the most common symptoms of histiocytosis are:

• Failure to gain height and weight
• Weight loss
• Irritability
• Fever
• Rash including on the scalp or diaper rash in infants
• Abnormal gums
• Discharge from the ear
• Bone pain, caused by swelling

Diagnosis

Your child's doctor may order one or more of the following tests to aid in the diagnosis of histiocytosis.

• Bone X-ray. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones and organs onto film.
• Skeletal survey X-ray. X-rays of the entire skeleton to determine the degree of bone involvement.
• Complete blood count (CBC). A CBC is a blood-screening test used to diagnose and manage numerous diseases. It can reflect problems with fluid volume, such as loss of blood. It can show abnormalities in the production, life span, and destruction of blood cells, which is an indication of an infection and problems with clotting.
• Biopsy. A biopsy of skin performed to check for the presence of Langerhan's cells.
• Bone marrow aspiration. Bone marrow obtained to check for the presence of Langerhan's cells. In bone marrow aspiration, cells are removed from the bone marrow, a spongy network of tissues inside the bones, to check for evidence of histiocytosis. Depending upon the diagnosis, this procedure may be done periodically throughout your child's treatment.
• Bone marrow biopsy. Immediately after a bone marrow aspiration, your child also may undergo a bone marrow biopsy to remove a small core of bone marrow. This procedure is necessary to confirm the presence of histiocytosis because the liquid part of bone marrow may not contain enough cells.

A bone marrow aspiration and biopsy usually takes 15 to 20 minutes to complete. Understandably, bone marrow aspirations may be frightening to you and your child. A local anesthetic is injected deep under the skin to numb the puncture site and takes effect quickly, helping to control the pain. Whenever possible, we give you the choice of having the procedure performed under general anesthesia.

A bone marrow biopsy is usually performed at the same site as the aspirate. Although the biopsy needle may look frightening, only a very small sample of the spongy bone marrow is removed, using a procedure similar to bone marrow aspiration. The difference is that a side-to-side motion of the needle is used to take out a small sample of the spongy bone marrow, which is the most painful part of the procedure.

Treatment

Histiocytosis is often treated with corticosteroids, which are anti-inflammatory drugs. Your child may be given other medications, including:

• Prednisone
• Methotrexate
• Vinblastine
• Mercaptopurine
• Cyclophosphamide
• Etoposide

In some cases, the disease regresses on its own. In other cases, radiation therapy and chemotherapy have been effective in treating the disease.