Langerhans cell histiocytosis (LCH) is a disorder in which people produce too many of a certain type of white blood cell that helps protect the body from infection (called Langerhans cells or histiocytes). In Langerhans cell histiocytosis, Langerhans cells grow out of control and build up, causing tumors called granulomas to form.
Langerhans cell histiocytosis primarily affects children, but it can also occur in adults.
There are four variants of Langerhans cell histiocytosis with different degrees of severity:
- Hashimoto-Pritzker disease
- Congenital
- Self-healing form
- Eosinophilic granuloma
- Less severe form
- Characterized by solitary or few, and chronic lesions of bone or other organs
- Hand-Schüller-Christian disease
- Intermediate chronic form with multiple lesions
- Characterized by diabetes insipidus, bulging of the eye, and localized lesions in the bone
- Letterer-Siwe disease:
- Severe, acute, widespread form
The five-year overall survival rates for Langerhans cell histiocytosis, that is, the percent of patients who are alive five years after diagnosis are:
- 99.8% with single-system involvement
- 98.4% for patients with multisystem disease without risk organ involvement
- 77.0% for patients with multisystem disease with risk organ involvement
What Are Symptoms of Langerhans Cell Histiocytosis?
Symptoms of Langerhans cell histiocytosis vary depending on the body part affected and how much of the body is involved. The disease can affect nearly every organ, including skin, bones, bone marrow, lymph nodes, lungs, liver, gastrointestinal tract, spleen, thymus, central nervous system, and hormone glands.
Symptoms of Langerhans cell histiocytosis based on the organ affected include:
- Skin
- Red, scaly papules in skin folds
- Skin symptoms usually improve without treatment
- Infants with skin presentation on the scalp may be misdiagnosed with cradle cap
- Collapsed lung (pneumothorax)
- Bone
- Often affects the skull, lower limbs, ribs, pelvis, and vertebrae
- Pain
- Swelling
- Limited motion
- Inability to bear weight
- Lung
- The most frequently involved organ in adults
- Difficulty breathing/shortness of breath
- Chronic cough
- Chest pain
- Lymph nodes
- Cervical lymph nodes (in the neck) are commonly affected
- Pain in the affected lymph node
- Liver
- Usually associated with more severe disease
- Buildup of fluid in the abdomen (ascites)
- Yellowing skin and eyes (jaundice)
- Low levels of protein
- Prolonged clotting time
- Central nervous system (CNS) and hormones
How Is Langerhans Cell Histiocytosis Diagnosed?
Langerhans cell histiocytosis is diagnosed with the following tests:
- Bronchoscopy with biopsy
- Skin biopsy
- X-rays
- Bone marrow biopsy
- Complete blood count
- Pulmonary function tests
- Liver function tests
- Magnetic resonance imaging (MRI) and computerized tomography (CT) scans of the head to check for abnormalities of the hypothalamus and the pituitary gland
- Fluorodeoxyglucose (FDG) positron-emission tomography (PET) scans for bone lesions
What Is the Treatment for Langerhans Cell Histiocytosis?
Treatment for Langerhans cell histiocytosis varies and depends on the variant of the condition, its severity, and the body part(s) affected. LCH will go away on its own in some cases.
Treatments for Langerhans cell histiocytosis can include surgery, chemotherapy, radiation therapy, and/or medications.
Treatment for Langerhans cell histiocytosis with asymptomatic isolated skin involvement includes:
- Topical medicines
- Steroids
- Nitrogen mustard
- Oral medicines
- Methotrexate
- Hydroxyurea
- Thalidomide
- Psoralen and long-wave ultraviolet A radiation (PUVA) or UVB
- Chemotherapy
- Radiation therapy
Treatment for Langerhans cell histiocytosis with skeletal involvement includes:
- Curettage or curettage plus injection of methylprednisolone
- Low-dose radiation therapy
- Chemotherapy
- Bracing or spinal fusion
- Bisphosphonate therapy
Treatment for Langerhans cell histiocytosis with central nervous system (CNS) involvement includes:
- Chemotherapy
- BRAF V600E inhibitor therapy
- Rituximab
- Tretinoin
- IVIG
Treatment of high-risk Langerhans cell histiocytosis multisystem disease (spleen, liver, and bone marrow involving one or more sites) includes:
- Chemotherapy
- Targeted therapy (BRAF inhibitors)
From 
Autoimmune Disease Resources
https://rarediseases.info.nih.gov/diseases/6858/langerhans-cell-histiocytosis
https://www.cancer.gov/types/langerhans/hp/langerhans-treatment-pdq#_91
https://moffitt.org/media/1284/328.pdf