Langerhans cell histiocytosis (LCH) is a group of rare disorders that overproduce and accumulate certain types of white blood cells (histiocytes) in organs and tissues in the body.
Histiocytes are part of the body’s immune system. In normal numbers, they help fight infection. When the body produces too many histiocytes, they actually attack the body’s healthy systems and can cause bone lesions or lesions in other organs.
Langerhans cell histiocytosis is rare. The incidence is approximately 1 to 200,000 children. It usually affects children younger than 12 years old and is more common among Caucasians than African Americans.
The majority of patients have a single bone lesion, but there is a spectrum of disease. Each type of LCH has different manifestations, presents with different symptoms, and has widely different outcomes.
The three syndromes that make up Langerhans cell histiocytosis are:
- Eosinophilic granuloma (most common). Single tumors (localized eosinophilic granuloma) occur most frequently in children aged 5 to 15 years. Boys are twice as likely as girls to have an eosinophilic granuloma. The condition can occur in any bone with common locations being the clavicle, pelvis and spine. When it manifests in the thoracic section of the spine, which is middle or chest area of the body, it can cause collapse of one of the vertebral bodies.
- Hand-Schüller-Christian disease. This chronic form of Langerhans cell histiocytosis is typically diagnosed before age 5. Hand-Schüller-Christian disease is often accompanied by diabetes insipidus, a condition in which the kidneys are unable to maintain water balance in the body and may present as frequent urination.
- Letterer-Siwe disease. This rare, and at times fatal, condition generally affects children age 3 or younger. It is characterized by skin lesions; enlarged liver, spleen and lymph nodes; anemia and bleeding tendencies.
The cause of Langerhans cell histiocytosis is unknown. It is not inherited or communicable. It can’t be passed from person-to-person like the flu or HIV. LCH may simply be an abnormality in a person's immune system, rather than a true tumor.
Doctors at Children’s Hospital of Philadelphia (CHOP) have participated in several research projects on this condition, looking into its causes and treatment outcomes.
Langerhans cell histiocytosis often causes no symptoms in children. Depending on the type of histiocytosis, symptoms may include:
- Localized pain for short periods of time, often at night
- Bone lesions
- Swelling or a bump/mass over a bone
- Fractures, particularly when the tumor is located in a weight-bearing bone
- Spine issues such as painful scoliosis or kyphosis
- Enlarged liver or spleen
- Diabetes insipidus
- Skin issues, including a skin rash or cradle cap (a scalp rash often in infants)
- Ear pain or recurring ear infections
- Low-grade fever
- Weight loss
Diagnosing Langerhans cell histiocytosis requires a careful and complete medical workup and examination of your child. Symptoms of LCH can be similar to benign bone lesions, such as aneurysmal bone cysts, fibrous dysplasia and others.
Because of this, clinicians at CHOP use a variety of diagnostic tests to correctly identify Langerhans cell histiocytosis in your child, including:
- X-rays, which produce images of bones.
- Magnetic resonance imaging (MRI), which uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs, soft tissues, muscles, ligaments and other structures within the body. Your child is exposed to no radiation during an MRI.
- Computed tomography (CT) scan, which uses a combination of X-rays and computer technology to produce cross-sectional images ("slices") of the body.
- Needle biopsy, which is a procedure where a doctor places a small needle through the skin and into the lesion to withdraw a small sample of the abnormal tissue. The tissue is analyzed to confirm any findings.
- EOS imaging, an imaging technology that creates 3-dimensional models from two planar images. Unlike a CT scan, EOS images are taken while the child is in an upright or standing position, enabling improved diagnosis due to weight-bearing positioning.
There are many treatment options available for LCH, and some children will need a combination of these therapies. At CHOP, experts at the Bone and Soft Tissue Tumor Program take a team approach to treatment. Orthopaedic and other pediatric specialists collaborate to provide your child with individualized care and the best possible outcomes.
Our program is led by Kristy L. Weber, MD, and Alexandre Arkader, MD, nationally renowned surgeons who specialize in treating bone and soft tissues tumors, limb-sparing surgery and reconstructive surgery.
Your child’s treatment for Langerhans cell histiocytosis will depend on how many organ systems are affected. If there are no neurological problems as a result of the tumor, your child’s physician may recommend “watchful waiting” — regular monitoring.
Most cases of Langerhans cell histiocytosis resolve on their own.
Some lesions resolve after a needle biopsy — a test used during diagnosis. In some cases, clinicians simply withdraw a sample of cells during the biopsy. In other cases, clinicians also inject a steroid into the lesion to promote healing. With or without a steroid, the biopsy appears to disrupt the lesion and cause it to dissolve. Doctors at CHOP are investigating why this occurs.
In more severe cases of Langerhans cell histiocytosis, medical or surgical treatment may be recommended.
Surgical treatment for LCH is generally a simple surgical removal of the lesion from the bone surface. In some cases, such as if the lesion was found on the spine, the affected bone may need to be reinforced with metal plates and screws on the outside of the bone or a metal rod placed inside the bone.
Low-dose chemotherapy may be recommended when Langerhans cell histiocytosis is more widespread throughout a child’s body, sometimes affecting multiple organs.
In rare cases, Langerhans cell histiocytosis affects a child’s spine and a temporary back brace may be recommended to treat or avoid kyphosis, a forward curve of the spine that can lead to a “hunchback” look. Kyphosis can prevent normal lung development and function. The bone affected by LCH heals without surgery.
Follow-up care for Langerhans cell histiocytosis will depend on which treatment your child received. If doctors recommended watchful waiting — and the lesion has not resolved — ongoing monitoring will be needed. During follow-up visits, X-rays and other diagnostic testing of the tumor site are recommended to closely monitor your child’s health.
One-third to one-half of all patients with a form of Langerhans cell histiocytosis will experience some complications ranging from physical disabilities to neuropsychological defects.
The more widespread forms of Langerhans cell histiocytosis can affect multiple areas of the body depending on the condition, so your child may need to follow up with a variety of clinical specialists in addition to an orthopaedic surgeon. Annual monitoring by experienced medical staff is strongly encouraged.
Follow-up care and ongoing support and services for your child and family are available at our Main Campus and throughout our CHOP Care Network. Our team is committed to partnering with parents and referring physicians to provide the most current, comprehensive and specialized care possible for your child.
Most children do well after a diagnosis of Langerhans cell histiocytosis. While many lesions resolve on their own, some may require treatment.
Patients with a single lesion generally have an excellent prognosis. Those with multiple lesions in one area of the body fare almost as well; while patients with disease throughout the body — such as those with Letterer-Siwe disease — face the most challenges.