Langerhans cell Histiocytosis in Adults

Langerhans cell histiocytosis (LCH) in adults is a rare disorder that occurs when the body produces too many Langerhans cells (histiocytes), which are a type of white blood cell that helps fight infection. While Langerhans cells are found in normal, healthy people, there is an over-production and build-up of these cells which can lead to organ damage in adults with LCH.

LCH Overview

Langerhans cell histiocytosis (LCH) is a rare type of blood disease that belongs to the group called histiocytic disorders or histiocytosis. LCH was previously considered an inflammatory or autoimmune disease but was recognized as a blood cancer in 2008 by the World Health Organization. This was partly due to the discovery of cancer-causing DNA changes (mutations) in BRAF- and other genes in biopsy samples from most patients.

LCH can affect children as well as adults and occurs more commonly in children. Among adults (ages 18 and over), the average age at diagnosis of LCH is around 40 years. The exact incidence of LCH is unknown and is estimated at 1-2 new cases per million population per year in the US. The disease-causing cells of LCH (histiocytes) can involve any organ system of the body from head to toe, but commonly affect the bones, lung, skin, or pituitary gland. Apart from the strong association of smoking and lung LCH, the cause of other forms of LCH is unknown. However, it is not considered a hereditary or contagious disease. The discovery of BRAF and other mutations has revolutionized the care of patients with LCH, resulting in targeted treatments that have the ability to improve patient survival.

The information on this page has been written and reviewed by the Histiocytosis Association Board of Trustees Scientific Committee and a member of the Histiocyte Society, and subsequently audited by patients and families to ensure enough information was captured. The most recent update to this page was in August of 2023.

Types of LCH

LCH can have variable manifestations, ranging from single site to multiple sites of disease. A “lesion” is a term used commonly to describe the area of involvement with LCH, which can also simply be called a “tumor.” According to the latest recommendations for treatment of adults with LCH, it is classified into the following 4 groups:

  • Unifocal: Single site (lesion or tumor) involving any organ
  • Single-system pulmonary: Isolated lung involvement (predominantly smoking related)
  • Single-system multifocal: More than one spot (lesion or tumor) involving any organ
  • Multi-system: More than one organ/system involvement
According to most experts, Langerhans cell Histiocytosis (LCH) is currently classified as a rare cancer and as of 2021, the National Comprehensive Cancer Network published clinical guidelines for histiocytosis classifying LCH, ECD, and RDD as histiocytic neoplasms. However, this doesn't necessarily mean that all of the worrisome implications that come along with the term “cancer” are true of LCH for every patient; LCH and other histiocytic disorders have a wide spectrum of presentations. 

Latest LCH Educational Webinar

Play Video

View additional webinars about Langerhans cell histiocytosis and other related topics, here. Explore our Educational Videos, here.

Signs & Symptoms

The symptoms of LCH depend on the number and degree of organ involvement. The following section discusses the frequency of organ manifestations and corresponding symptoms experienced by patients with LCH. It is important to note that not all organ manifestations may result in symptoms.

  • Bones (30-50%): LCH can involve any bones within the body, although most commonly involves the skull, teeth, spine, ribs, or hip bones. In bone, LCH can present as unifocal (one location) or multifocal (two or more locations) bone disease. Symptoms of bone involvement include pain or swelling of the head, jaw, back, or other bones of the body.
  • Skin (30-50%): Skin involvement mostly occurs in combination with other disease sites (multisystem) but can involve the skin alone in 10-20% of cases. It is most commonly seen as red or brown rash with formation of flakes or crusts, and often on the chest, back, belly, arms, legs, head, or groin region. Rarely, it can cause a rash or ulcers in the mouth or genitals (vagina, penis, anus). Symptoms of skin involvement include red or brown rash, bumps, ulcers.
  • Pituitary gland and hormone deficiencies (25-30%): Pituitary involvement most commonly presents as diabetes insipidus (arginine vasopressin-deficiency), and is often the first manifestation of the disease. The occurrence of diabetes insipidus (DI) also known as arginine vasopressin-deficiency (AVP-D) can precede the diagnosis of LCH by years and sometimes even decades. Among all individuals with DI/AVP-D, histiocytosis (LCH or ECD) can be the underlying cause in 10% of cases. Other pituitary hormone deficiencies that are commonly seen in LCH are growth hormone, gonadotropin, thyrotropin, and corticotrophin. The pituitary hormone deficiencies may or may not be associated with abnormal pituitary MRI scans. DI/AVP-D and other hormone deficiencies caused by LCH do not typically resolve despite successful treatment of LCH and patients need lifelong monitoring and hormone replacement. In children and young adults with LCH, pituitary involvement can be associated with development of neurodegenerative disease many years later (see section on nervous system below). Symptoms of pituitary involvement include excessive thirst and urination, fatigue, swollen thyroid gland, low libido, cold intolerance, weight gain, menstrual problems in women, erectile dysfunction in men.
  • Nervous system, including the brain and eyes (5-10%): Direct LCH involvement of the brain is rare, but it can involve the parts of the brain that control balance and coordination (brainstem and cerebellum). It can also affect the spinal cord and nerves arising from it. Occasionally, the nervous system can be affected by the growth of LCH tumors from bones of the skull or spine into the brain or spinal cord, respectively. Special imaging of the brain (MRI) is required to assess the involvement of the nervous system by LCH. Very rarely, LCH can lead to degeneration of the brain cells (called neurodegenerative disease), which can occur many years after initial diagnosis and treatment. Symptoms of nervous system involvement include difficulty with coordination, difficulty maintaining balance, recurrent falls, slurred speech, behavior disorders, learning difficulty, difficulty seeing.
  • Lung and respiratory system (40-50%): Mostly seen as disease isolated to the lungs (single-system pulmonary LCH) in individuals who are cigarette smokers but can also be seen as a part of multi-system disease. It is believed that cigarette smoke attracts specific immune cells in the lungs leading to injury and damage to the airways over time, thereby affecting the ventilation and oxygenation functions of the lung. Recently, cancer-causing mutations in the BRAF and other genes have also been found in cases with single-system pulmonary LCH, suggesting that a large proportion of these may be cancerous. Single-system pulmonary LCH rarely spreads outside of the lungs (less than 5%), and in early stages is entirely reversible by quitting smoking completely. Lung involvement affects the ventilation and oxygenation functions of the lung. The most common test to assess for lung involvement is a computed tomography (CT) scan, which can show small tumors (called nodules in the early stage) or cysts (in the later stage) mostly in the upper and middle parts of the lungs. Tests to assess the function of the lung (pulmonary function tests) are usually conducted. If left untreated, it can lead to the need for oxygen and increased pressure on the heartTreatment for cases with single-system pulmonary LCH is often provided by lung specialists (pulmonologists); however, involvement of a cancer specialist (hematologist/oncologist) is often necessary especially if the disease is not improving with smoking cessation counseling alone. Symptoms of lung and respiratory involvement include chest pain, shortness of breath, sinus congestion, collapsed lung, dry cough, weight loss, fatigue, loss of appetite, night sweats, coughing up blood. Some patients may have little to no symptoms at all.
  • Liver and spleen (10-15%): Liver and spleen involvement is seen mostly in cases with multisystem disease. Liver involvement can present in two ways: a) tumors or the liver and liver enlargement, or b) involvement of the bile ducts called as sclerosing cholangitis that can progress to end-stage liver disease. Changes in the liver can be seen on ultrasound scan or a special type of MRI scan of the liver. Symptoms of liver and spleen involvement include abdominal pain, jaundice (yellowing of eyes and skin), nausea and vomiting.
  • Lymph nodes (10-30%): Isolated involvement of lymph nodes by LCH is rare in adults; lymph node involvement occurs mostly in multisystem disease. It is important to conduct a surgical biopsy of the enlarged lymph node to confirm the diagnosis of LCH and rule out other conditions. Reactive Langerhans cells in lymph nodes can be seen in other forms of inflammatory conditions and do not necessarily represent LCH. Symptoms of lymph node involvement include (usually asymptomatic) enlargement of lymph nodes in the neck, armpits, or groin.
  • Bone marrow (frequency unknown): Bone marrow can be involved by LCH in a small proportion of cases. LCH has also been associated with blood cancers such as acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), myeloproliferative neoplasm (MPN), and chronic myelomonocytic leukemia (CMML). Symptoms of bone marrow involvement include abnormally low or high blood cells on routine testing (Complete Blood Count or CBC) however patients are usually asymptomatic.
  • Gastrointestinal and cardiovascular system (rare): Gastrointestinal involvement can occur in the form of small tumors (polyps) in the intestine. LCH does not involve the heart or blood vessels typically, and such a presentation should raise the suspicion for ECD. Symptoms include diarrhea and abdominal discomfort.
  • Teeth/Gums (frequency unknown): Loosening or loss of teeth, swollen or bleeding gums, ulcerations, pain, swelling of face.
  • Ears (frequency unknown): Chronic ear infections, drainage/discharge, balance problems, bleeding, decreased hearing. Ear involvement can be a result of skull lesions expanding to the ear and may cause balance problems. Ear canals may be affected as part of the skin system, causing bleeding/drainage.
  • Female Genital/Reproductive Tract (frequency unknown): Can occur as inflammation, rash, and/r=or ulceration of the vulva, vagina, and/or cervix, but it may also affect the ovaries, causing dysfunction or failure of these organs.
  • Additional Non-specific Symptoms include low-grade fevers, weakness, fatigue, chronic pain, weight loss, night sweats, depression, memory difficulties, muscle and joint aches. 

Pulmonary LCH (PLCH) can occur as part of multi-system disease, or it can occur alone. Nearly 20% of adults with PLCH have no presenting symptoms. An estimated 10%-15% of patients present with lung collapse as the first symptom, while others may show abnormalities in lung function tests. Dry cough and shortness of breath are the most common complaints, and weight loss, fever, sweats, and loss of appetite occur in approximately 33% of patients.

Many adults experience severe and sometimes overwhelming pain associated with this disease. While pain can be caused by bone lesions or bone defects that do not heal completely with therapy, it has also been observed that some patients have pain even when there is no active disease seen on x-ray. The cause of this pain is not understood; however, it is being currently explored in research. Pain is considered a complication of LCH that should be fully evaluated by a physician and treated with appropriate medications.

NCCN Guidelines Published in 2021

The National Comprehensive Cancer Network® (NCCN®) - an alliance of leading cancer centers - announced the publication of new NCCN Guidelines® for histiocytosis. These clinical practice guidelines provide the latest evidence and expert-consensus for diagnosing and treating the three most common forms of histiocytosis in adults: Langerhans cell histiocytosis (LCH), Erdheim-Chester Disease (ECD,) and Rosai Dorfman Disease (RDD). Although the guidelines are focused on adult patients, there may be insight for pediatric physicians as well. The Guidelines are listed as "histiocytic neoplasms" and can be found on NCCN's website.

You can find international expert consensus recommendations for the diagnosis and treatment of Langerhans cell histiocytosis in adults, here. You can download a copy, here. It is encouraged that you share this with your physicians for reference.

On November 1st, 2022, Memorial Sloan Kettering Cancer Center (MSK) announced that the U.S. Food and Drug Administration (FDA) has approved the oral MEK inhibitor drug cobimetinib (Cotellic®) for the treatment of adult patients with the family of blood diseases known as histiocytic neoplasms (HN). These diseases include Erdheim-Chester disease, Rosai-Dorfman disease, and Langerhans cell histiocytosis. Cobimetinib is an oral inhibitor of MEK1 and MEK2, currently approved to treat melanoma. Gratitude and congratulations to the Principal Investigator of this study, Dr. Eli Diamond, neuro-oncologist and neurologist at MSK and Chair of the Scientific Committee for the Histiocytosis Association. We applaud the efforts of Dr. Diamond and the entire study team for this tremendous advancement. Read more here.

The diagnosis of LCH is made following a biopsy of the affected tissue. 

The diagnosis of LCH relies on the review of the biopsy of a tumor specimen under the microscope. In some cases, the classic findings of LCH may not be present or it might be difficult to obtain a tissue biopsy due to the location of the disease. In those instances, a diagnosis of LCH can still be made in the presence of characteristic clinical and radiographic features especially in conjunction with a mutation in the MAPK/ERK pathway. Some of the characteristic features of LCH include a) “punched out” bone lesions of the skull, jaw, spine, ribs, or hip bones and b) cysts or nodules in the upper part of the lungs in a smoker. A PET CT scan (head to toes) is the preferred imaging study as it also allows to search for other sites of disease more accurately as compared with other radiographic tests (see explanation of PET scan below).

A biopsy of one of the affected sites from LCH using a needle or through surgery is usually conducted and reviewed by an expert pathologist under the microscope for features suggestive of LCH. Often there are many other inflammatory cells mixed with the LCH cells in the biopsy specimen. A special test called an immunohistochemistry is undertaken by using stains (dyes) that check for certain markers (antigens) in the tumor sample. The stains are referred to as “positive” if the tumor cells bind to the dye and are visible under the microscope and referred to as "negative" if they do not. LCH cells are positive for the markers CD68, CD1a, and Langerin. In addition, testing for mutations of the BRAF and other genes through special tests called next generation sequencing (NGS) studies on the biopsy specimen or blood may be undertaken to help aid in the diagnosis or treatment. There are many laboratories that conduct NGS, and it is recommended to discuss with your doctor about which one to use for your case. (Learn more about these tests, here, toward the bottom of the page.)

In cases where the classic features under the microscope are not present (5% of the time), the presence of a mutation in combination with other features mentioned above may lead to a diagnosis of LCH.

Baseline Evaluation and Testing

Once the diagnosis of LCH is made, detailed history, physical examination, and specific tests are undertaken to determine the extent of the disease, i.e., determining what organs are involved with the disease and how severe. Below are descriptions of these baseline evaluations and tests.

  • History: A detailed health history including onset and duration of symptoms, past illnesses, health and lifestyle habits, and medical conditions experienced by the patient and their family.
  • Physical Examination: Includes a detailed exam of the body to search for signs of LCH. A specialized neurological exam may also be undertaken to evaluate if LCH has affected the brain and the nervous system, and includes testing for reflexes, coordination, and memory.
  • Blood Tests:
    • Complete blood count (CBC): to check for hemoglobin, platelets, and different types of white blood cells. (Hemoglobin is protein in your red blood cells that carries oxygen to your body's organs and tissues and transports carbon dioxide from your organs and tissues back to your lungs. Platelets are clotting agents in cells. White blood cells are cells of the immune system that fight infections and diseases.)
    • Blood chemistry tests: Studies for kidney, liver, coagulation, thyroid and immune function; abnormal level can be a sign of disease. Complete blood count, sedimentation rate, liver function tests, and electrolytes may be studied.
    • C-reactive Protein (CRP): a marker of inflammation which can be elevated in LCH.
    • Urine and Serum Osmolality / Water Deprivation Test: to check if the LCH has affected the pituitary gland hormone that helps to regulate the concentration of urine is being secreted accurately.
    • Other hormone tests: to assess whether LCH has affected endocrine organs such as the pituitary gland, thyroid gland, or the adrenal glands.
    • BRAF and other Gene Mutation testing: to check for gene mutations include BRAF-V600E and other mutations in the blood.
  • Tests on the Biopsy Specimen:
    • Immunochemistry: This test uses various types of dyes to find markers that can help in the diagnosis of LCH and differentiate it from other diseases. At times, BRAF-mutation testing can also be achieved relatively quickly using immunohistochemistry methods.
    • Molecular Testing: This test involves testing the tissue for changes in the BRAF gene, especially the BRAF-V600E mutation, as well as other mutations that can be driving the LCH (KRAS, NRAS, etc.). Some of these tests require sending the biopsy sample to a specialized laboratory that can take several days to weeks to result. Knowledge of these mutations can help with the diagnosis and treatment of LCH.
  • PET (positron emission tomography) scan: To check for tumor cells in the body, a small amount of radioactive sugar is injected into a vein followed by taking pictures in a PET-scanning machine. The disease-causing cells look brighter than surrounding cells due to increased uptake of glucose.
  • CT (computed tomography) scan: This is an x-ray that takes a number of detailed pictures of various organs and structures within the body, often conducted in combination with a PET scan. Dye may be injected into a vein or taken by mouth to make the images clearer. Sometimes, a high-resolution CT scan of the chest is conducted if there is suspicion of pulmonary (lung) LCH.
  • Bone scan: This is a type of x-ray that looks for areas of tumor cells growing in the bones. A small amount of radioactive material is injected into a vein, collects in any abnormal parts of the bones, and is detected on a scanner.
  • MRI (magnetic resonance imaging): A special type of scan that used magnetic waves to obtain detailed pictures of various body parts. A substance called gadolinium may be injected into a vein to get clearer pictures. Sometimes, a special MRI of the liver is conducted if there is suspicion of LCH involvement. This procedure is called magnetic resonance cholangiopancreatography (MRCP).
  • Pulmonary Function Test (PFT): Also called a lung function test, it is a breathing test to evaluate the function of the lungs. This test measures the capacity of the lungs to hold air, inhale, exhale, and exchange oxygen with carbon dioxide in the air.
  • Bronchoscopy: A procedure to look for abnormal areas inside the windpipe (trachea) and lung airways using a special camera called a bronchoscope. The bronchoscope is introduced through the mouth under sedation. This procedure can be used to obtain biopsy material.
  • Endoscopic Retrograde Cholangiopancreatography (ERCP): When involvement of the digestive tract is suspected, this procedure can be used to diagnose and treat problems in the liver, gallbladder, bile ducts, and pancreas. ERCP combines the use of x-rays and a special tube with camera.
  • Ultrasound: This is a procedure where sound waves are used to create echoes and collect pictures of organs.
  • Electrocardiogram: This is a tracing of the heart rate and rhythm.
  • Echocardiogram: This uses sounds waves to provide pictures of the heart in order to evaluate blood flow and heart function.
  • Bone Marrow Aspiration and Biopsy: This procedure involves suctioning of a small amount of bone marrow and taking a small piece of the bone by inserting a hollow needle in the hip bone.
  • Specialist Examinations: This may include a neurological examination to test ability to walk, coordination, etc.; lung specialist evaluation if there is concern for pulmonary LCH; urinalysis to test the number of red cells, white cells, protein and sugar in the urine; other specialist visits or specific testing may be recommended by your physician (See Treatment section below).

If there are symptoms of diabetes insipidus, a water-deprivation test should be done. When the bones near the ears or eyes are involved, a head CT scan is indicated. An MRI of the brain may be necessary if the lesions are near the eyes or ears or there is suspicion of central nervous system (CNS) involvement. Chest CT and lung function studies are performed when indicated. Other testing may be done, depending on symptoms. Other biopsies may be performed if test results or abnormal findings during the physical exam cause the physician to suspect involvement of another area.


In many diseases or cancers, there is the concept of “staging” which refers to the extent or severity of the disease within the body (for example, “stage 4 lung cancer.” There is no standard staging system for LCH. The severity of the disease is determined by how widespread the involvement occurs outside of bone and whether internal organs are affected. 


General Principles of Treatment

The treatment LCH often depends on the degree of organ involvement at diagnosis. In some patients who do not have any symptoms or any critical organ involvement like brain, liver, or spleen, it is reasonable to pursue a "watch and wait” strategy for some time without treatment. In these cases, close monitoring by a specialist is needed, and may include repeated imaging studies like PET scan or CT scan. Patients with LCH should have their treatment planned by a team of health care providers who are experts in the disease, including and not limited to the following:

  • Cancer specialist (hematologist/oncologist) 
  • Hormone specialist (endocrinologist) 
  • Autoimmune disease specialist (rheumatologist) 
  • Lung specialist (pulmonologist) 
  • Brain and nervous system specialist (neurologist) 
  • Skin specialist (dermatologist)
  • Ophthalmologist (Eye Specialist)   
  • Psychologist and supportive care specialist 
Treatments Available for LCH

The treatment approach to LCH has evolved significantly due to discovery of mutations in the BRAF and other genes, leading to the successful use of targeted therapies in most cases. Treatments for LCH can be divided into two categories: targeted and conventional treatments. Patients may also consider enrolling in a clinical trial if available near them. 

Targeted Therapies

Targeted therapies include treatments that attack specific genes or protein in the cancer cells. These drugs have not been extensively used in LCH, and their use is typically reserved to situations where other conventional treatments are unsuccessful or when LCH causes severe illness, and a quick response is needed. Targeted therapies are likely required to be taken for a long time, as there is concern that the LCH will recur upon stopping the drug. There are different types of targeted therapies available for LCH 

  • BRAF-inhibitors (vemurafenib, dabrafenib, encorafenib): These drugs are typically used when there is presence of the BRAF-V600E mutation in the tumor cells. These drugs are taken by mouth and the dose can vary based on side effects and response to treatment. The common side effects include skin reactions (rash or skin cancer), joint pains, and fatigue. Seeing a skin doctor regularly can help with management of these effects. Other less common but important adverse effect is abnormal heart rhythm or reduced heart function. Some patients on these drugs will get routine electrocardiograms and echocardiograms to monitor the effects on the heart. Some of the side effects may necessitate switching from one type to BRAF-inhibitor to another.
  • MEK-inhibitors (cobimetinib, trametinib, binimetinib): These drugs are typically used when there is no BRAF-V600E mutation in the tumor cells. These drugs are taken by mouth and the dose can vary based on side effects and response to treatment. Common side effects include skin rash, and patients may need to see a skin doctor for management. These drugs can also reduce the heart function, and sometimes an echocardiogram may be needed to monitor the effects on heart. Another notable side effect is changes in the layer of the tissue in the back of eye that senses light (retina) leading to blurry vision or loss of vision. It may be necessary to get regular eye exams while on treatment with these drugs.
Conventional Therapies

Conventional therapy is the therapy that is widely used and accepted by most healthcare professionals. There are different types of conventional therapies available for LCH 

  • Chemotherapy (cladribine, cytarabine, hydroxyurea, vinblastine + prednisone, methotrexate + cytarabine): These drugs are given through the vein and are often the preferred treatment in cases with single-system multifocal disease, multi-system disease, or cases involving high-risk organs (brain, liver, spleen). Chemotherapy works by slowing the growth of or killing rapidly dividing tumor cells. These drugs have the potential to weaken the immune system and can lead to infectious complications. Vinblastine can cause damage to the nerves leading to neuropathy, manifesting as numbness, tingling, or pain of fingers and toes. Cladribine can increase the risk of a particular type of pneumonia (pneumocystis pneumonia) so preventative antibiotics may need to be administered alongside. Prednisone can lead to weight gain, stomach upset, sleep disturbances, and increased blood sugar. Methotrexate, when given through the vein in high dose, can lead to reduced kidney function or kidney failure. Methotrexate in combination with cytarabine can cause increased risk of infections and low blood cell count. Hydroxyurea can cause mouth sores, darkening of skin, rash, and rarely leg ulcers.
  • Immunosuppressant and immunomodulator (thalidomide, lenalidomide, corticosteroids, low dose oral methotrexate): These are drugs given typically through mouth, except for corticosteroids, which can be given through injection or as a topical treatment (cream or lotion). These agents are often used in LCH involving the skin or bones. These drugs work by suppressing the immune system and reducing the inflammation induced by the tumor cells. Thalidomide and lenalidomide should not be taken by reproductive age women who are trying to get pregnant as it can cause severe birth defects in the child. Thalidomide can cause damage to the nerves leading to neuropathy, manifesting as numbness, tingling, or pain in fingers and toes. Thalidomide and lenalidomide can lead to increased risk of blood clots in the veins and can also decrease the production of blood cells. Corticosteroids when given through vein or mouth can lead to weight gain, stomach upset, sleep disturbances, and increased blood sugars. Oral low dose methotrexate can lead to stomach upset, mouth sores, liver damage, lung damage, and decreased production of blood cells.  
  • Other treatments (smoking cessation, surgery, radiation, zoledronic acid): Smoking cessation can lead to reversal of pulmonary LCH. Surgery may be used to remove LCH lesions from the bone, lymph node, or under the skin. Occasionally, radiation therapy using high energy x-rays or protons may be used to kill tumor cells, especially in the bone. The side effects of radiation can depend on the site of radiation and the amount of normal tissue exposed to the radiationZoledronic acid is given through the vein and can lead to shrinkage and reduced pain from bone lesions.  
Treatment Approach in Adults with LCH

The treatment options for various forms of LCH are listed below:

  • Unifocal (one location) LCH of the bone:
    • Limited surgery called as curettage-can sometimes lead to complete response
    • Radiation therapy
    • Chemotherapy in case of large lesions or involvement of regions that are not easy to perform surgery on (skull, eye socket, hip bone, spine)
    • Immunosuppressant or immunomodulator therapy
  • Multifocal (more than one location) LCH of the bone:
    • Radiation therapy for 2-3 spots
    • Zoledronic acid
    • Chemotherapy, single agent or combination
  • Single-system Pulmonary LCH:
    • Smoking cessation: quitting smoking in all forms (tobacco, marijuana, vaping). Sometimes this is the only treatment required and can lead to complete reversal of disease
    • Corticosteroids can help with symptoms
    • Chemotherapy, single agent or combination 
    • Targeted therapies 
  • Unifocal (one location) or multifocal (more than one location) Skin LCH:
    • Observation (watch and wait) for asymptomatic disease
    • Topical (cream or lotion) or injectable corticosteroid (hydrocortisone, triamcinolone)
    • Thalidomide, lenalidomide, hydroxyurea, or low dose oral methotrexate
    • Chemotherapy
  • Multifocal and multi-system disease without critical organs (brain, spleen, liver, lungs):
    • Chemotherapy, single agent, or combination
    • Targeted therapies
    • Radiation in some cases with limited spots of LCH
  • Critcal organ involvement (brain, spleen, liver, lungs):
    • Chemotherapy, single agent or combination
    • Targeted therapies
Monitoring on Treatment

Once treatment is initiated, patients need follow-up tests or monitoring for assessing the response to therapy and also management of side effects of treatments. Some of the tests that may be undertaken include:

  • Physical exam, including neurological exam
  • Skin exams in patients on BRAF and MEK-inhibitor treatments
  • PET scan to check for reduced brightness and size of the tumor sites
  • Additional imaging studies (CT, MRI) may be undertaken based on organs involved at diagnosis. Imaging (PET, CT, MRI) is usually repeated every few months and can be variable for each patient
  • Blood tests to assess for changes from the disease or the treatments
  • Hormone evaluation and treatment with the help of an endocrinologist
Treatment of Relapsed LCH

If LCH grows back after treatment, it is referred to as relapsed disease and if it does not respond to treatment at all, it is called as refractory disease. In such cases, one of the targeted or other conventional treatments than used previously may be utilized. In some cases, a repeat biopsy of tumor cells may be needed for confirmation of diagnosis and mutation testing. If a clinical trial is available, that may be a consideration as well.  

Supportive Care

Despite improvement in treatments, several patients with LCH struggle with many symptoms such as extreme tiredness, body pain, depressed mood, anxiety, and memory difficulty. In many cases, getting additional input from psychology, supportive/palliative care, psychiatry, and pain specialists may be helpful. Leading a healthy lifestyle (exercise, balanced diet) may help improve some of these symptoms in addition to medications. Diabetes insipidus and other hormone deficiencies caused by LCH do not typically resolve despite successful treatment of LCH and patients need lifelong monitoring and hormone replacement. LCH survivors can also struggle with neurological problems from involvement of brain or spinal cord, or musculoskeletal issues from lesions of bones in the arms or legs. Children and young adults with pituitary involvement from LCH are at a high risk of developing neurodegenerative LCH later on in life (years to decades later), which manifests as difficulties with balance, behavior, and memory. 


The prognosis of LCH has continued to improve with the introduction of newer treatments and early diagnosis. As patients with LCH live longer, they may be at a risk of other health problems from the treatments or as a process of getting older. People with LCH are also at a higher risk of other cancers than those without LCH. It is important for patients to continue to follow up with their healthcare provider to monitor for second cancers or side effects of treatment.   

Permanent Consequences

More recent advances in research and treatment of histiocytic disorders have provided a high survival rate for patients with this disease. At the same time, as more patients have been followed long-term, the risk for permanent consequences has become more obvious. It is now known that survivors can have significant consequences related to the disease and/or its treatment, sometimes following long-term remission. Most of these issues tend to be directly related to sites of original disease involvement and may affect quality of life. It is believed that more than half of patients will develop permanent consequences.

Also known as “late effects,” some consequences such as neurologic symptoms may not show up until 10 or more years after diagnosis, while other consequences such as diabetes insipidus can occur when histiocytosis is diagnosed, or even before. For this reason, “permanent consequences” has been suggested as a better term than “late effects.” Although some consequences such as tooth loss, bone defects, and scarring of the skin may be the result of surgical treatment, it is believed that the disease process itself is responsible for most of the effects.

Permanent consequences occur more often with multisystem patients but are also seen in patients with single-system disease at diagnosis. In one study, over 70% of multisystem LCH patients had one or more permanent consequences, compared to 24% of single-system patients. Children are more at risk to develop consequences because the disease can interfere with growth and development, and the consequences have a longer time to develop.

Some examples of permanent consequences include:

  1. Diabetes insipidus (DI)/ArginineVaspopressionDeficiency(AVP-D)
  2. Stunted growth/failure to achieve sexual maturity
  3. Defects of bone/skull defects/facial asymmetry
  4. Loss of spinal height
  5. Loss of teeth/part of jawbone
  6. Bulging of the eyes
  7. Hearing loss
  8. Scarring of the skin
  9. Scarring of the liver
  10. Scarring of the lung
  11. Secondary cancers
  12. Neurologic/cerebellar problems, which can include:
    • Poor coordination/difficulty walking
    • Bad handwriting
    • Tremor/abnormal eye movements
    • Difficulty with balance/unsteadiness/clumsiness
    • Problems with speech and/or swallowing
    • Loss of short-term and/or long-term memory
    • Learning difficulty/poor school performance
    • Difficulties with concentration/attention/processing
    • Lower IQ score
    • Organizational difficulties
    • Behavior changes including aggression, eating disorders, depression, and difficulties with interpersonal relationships

The exact incidence of diabetes insipidus (DI) is not known, but it is believed to be in the range of 5% to 50% of LCH patients, depending on the location and extent of disease. The risk of developing DI in patients with multisystem LCH is 4 to 6 times greater than those with single-system disease. Patients with skull, facial, and/or eye bone lesions are at much higher risk of developing DI, and this risk is increased further if the disease remains active for a longer period or if it recurs. Although once established, diabetes insipidus cannot be cured, it can be successfully treated with a hormone called DDAVP.

Stunted growth is the most common endocrine abnormality and occurs in approximately 10% of children with histiocytosis. It was shown in one study to occur in 43% of patients who had diagnoses of both LCH and diabetes insipidus. Stunted growth can be successfully treated with daily injections of growth hormone, usually for as long as the child is growing. This treatment appears to be safe and effective and is not associated with an increased risk of disease reactivation.

Orthopedic problems from lesions of the spine, leg bones, and arm bones are one of the more common consequences and may be seen in 20% of patients. These problems include collapse of the vertebrae, instability of the spine that may lead to abnormal spinal curvature, decreased spinal height, fractured bones, and inequality of leg length. In addition, since the skull and facial bones are frequent sites of lesions, abnormalities and asymmetry of the face may occur. Some bone/facial abnormalities can be corrected by orthopedic or cosmetic surgery.

Dental problems with loss of teeth have been a significant problem for some patients, either directly related to disease affecting the jaw or related to aggressive surgery for jaw disease. The potential for restoration/cosmetic repair can be discussed with a knowledgeable physician. Residual eye bulging can affect one or both eyes. Hearing loss was found in one study to affect 16% of children treated for LCH. Of those with CT or MRI abnormalities of the mastoid, 59% had hearing loss. Inner ear involvement has been known to cause loss of balance. Hearing aids or surgically inserted electronic hearing devices (cochlear implants) may be necessary.

Liver disease may lead to scarring and destruction of the liver and, in rare cases, liver failure which may require transplantation. Lung disease is believed to occur in less than 10% of patients, causes scarring and damage of lung tissue, and can result in long-term poor lung function with a higher risk for infections, shortness of breath, and lung collapse. In cases of severe damage, a lung transplant may be necessary for survival. Permanent damage, however, is less common in children, whose lung tissue can more easily regenerate. Patients with a history of lung involvement may have a lifelong susceptibility to lung disease associated with cigarette smoking.

Patients with histiocytosis have a slightly higher chance of developing secondary cancers when compared to the unaffected population; secondary cancers could include leukemia, brain tumors, and cancer of the lung, liver, bone, lymph nodes, and eyes. It has not been determined whether this is caused by treatment or a genetic predisposition. Cancer can occur at the same time as histiocytosis or can occur years afterwards.

Neurologic problems with cognitive deficits, behavioral disturbances, and neuromotor dysfunction, also known as central nervous system (CNS) involvement, are reported to affect at least 10% of all LCH patients (19% of all multisystem patients). (For other histiocytic disorders, studies of greater numbers of patients are necessary to better define how often this occurs.) It is believed that this phenomenon is more frequently recognized now that more patients with histiocytosis are being followed long-term. It is characterized by symptoms in the brain that may not manifest until 10 or more years after initial diagnosis. Although this is usually seen on MRI scans, it may occur when there are no abnormal findings on MRI. The CNS complications can remain stable for years or can be progressive and become debilitating. No effective treatment has yet been developed; however, various forms of rehabilitation and teaching assistance can be helpful for these patients. These include assistance with learning and life skills; education about permanent consequences; teaching of repetition, reinforcement, and organizational skills; and placement of school/job accommodations. While the neurologic issues cannot be reversed, caregivers can provide tools that will help the patient increase his/her level of success.

In addition to compromised physical/cognitive function, histiocytosis survivors may experience quality-of-life issues such as anxiety/fear about possible relapse, sadness, anger, and depression. These feelings may be especially strong before follow-up visits, on illness-related anniversaries, or with onset of symptoms not related to the disease. For many people, these feelings will go away over time, while others may need psychological or psychiatric support. Finding a supportive network of other histiocytosis survivors can also be helpful.

  • On-line: You can subscribe to receive our emails so that you receive our newsletters, and you will also receive important announcements regarding the latest information and research developments on the histiocytic disorders. The Association also maintains a Facebook page and private Facebook group for families and patients with this disease.
  • Local support: The hospital where you or your child is being treated may have a support group for survivors of histiocytic disorders, rare diseases in general, or even cancer. Establishing face-to-face relationships with others going through similar experiences can be helpful.

Because of the possible impact of permanent consequences on school/job performance, ability to lead an independent life, and overall quality of life, it is important that the patient be evaluated and followed long term, especially those with multisystem disease. Early recognition of any deficit will be important, so that appropriate rehabilitation and assistance can be planned and put into place.

After years of research and discussion among researchers, there are still considerable gaps in the understanding of histiocytosis and its neurological complications. Some authorities believe it is a process separate from disease activity, and others believe that early, effective therapy may prevent or reduce the complications.

In order to make further progress in this field, the Histiocyte Society has developed a clinical trial/study called LCH-IV which opened for registration in 2012 and is on-going. This includes new guidelines for diagnosis and treatment of CNS LCH, including repeated MRIs, standardized neurologic evaluation, and neuropsychological tests for all patients with CNS disease. The study will test whether longer therapy for active disease will reduce the rate of reactivation and development of complications. You may consult your health care provider to find out about possible treatment options.

If you are a histiocytosis survivor with permanent consequences, it will be important to educate yourself about available resources and stay updated about the latest research findings. This information will help you make informed decisions and play an active role in acquiring the best support and services available. In doing so, you will create the best chance for a successful outcome.


What Do I Do Now?

A new diagnosis of Langerhans cell histiocytosis (LCH) can bring feelings of being overwhelmed, bewildered, scared, angry, sad, disappointed, helpless, and sometimes even feelings of guilt.  It is a time filled with unknowns, change, and new people and situations.  Most patients feel ill-equipped to understand what is happening to them and how to navigate through the illness to recovery.  There are, however, strategies and resources that can help you and your family get through the uncertain times that lie ahead.  One step at a time, you can gather information, create a support system, learn how to cope with stress, and become a strong self-advocate and part of the medical team.  The following tips and suggestions are provided to help guide you through this journey toward recovery.

LCH referral care centers and specialists: LCH Referral Care Centers and disease specialists are available to treat patients and/or provide consultation to local treating physicians when patients cannot travel.  The Histiocytosis Association maintains a list of such centers and physicians here. 

Education & Connection: here are numerous opportunities to receive education on disease and connect with experts through online lectures (webinars) and in-person patient and family events. To stay connected with all the updates, you can sign up to receive emails, view on-demand webinars and educational videos, join a peer-to-peer support call, tune into our podcast, or attend a regional meeting. You can also reach us at 1-856-589-6606 or - we want to connect!

Take Part in Research: People are needed for clinical studies that can help find effective treatments and improve for patients with LCH. These studies can be either interventional (to find effective treatments), translational (to collect samples like blood, saliva, tumor for finding new targets for treatment), or observational (to study health effects of the disease or treatments). There is an ongoing study for patients with LCH and other histiocytosis- the Histiocytic Disorder Survivor Study (HDSS). This study is a partnership between the Histiocytosis Association and the University of Alabama at Birmingham, and involves filling up a survey about your health conditions from the comfort of your home. For more information, call 1-866-438-1640 or email  

Articles and Links



Printable Fact Sheets

Learn more about the different types of histiocytic disorders from these helpful fact sheets. Printing these for family and friends is a quick and easy way to teach them about the disease. More extensive information can be found in the Disease Information section of our website.

Choose from the following Fact Sheets: