Disease Description (Causes and Symptoms)
- Definition and pathophysiology: Langerhans cell histiocytosis (LCH) is a disease in which clonal proliferation of Langerhans cells (antigen-presenting dendritic cells) causes infiltration and destruction in multiple tissues. Mutations in signaling pathways, such as BRAF V600E, are observed in some patients. Clinically, it presents as single-system or multisystem disease, and involvement of the so-called “risk organs,” including the liver, spleen, and bone marrow, affects the prognosis.
- Main symptoms:
- Bone lesions: localized pain, swelling, osteolytic lesions (common in the skull), vertebral compression fractures, fractures
- Skin: rash (papules and vesicles), pustules, ulcers (on the scalp, extremities, etc.)
- Internal organs/blood: hepatosplenomegaly, splenomegaly, hypoproteinemia, ascites, jaundice, anemia, bleeding tendency
- Lungs: cough, shortness of breath, tachypnea, pleural effusion (characteristic worsening in adult smokers)
- Central nervous system/endocrine: central diabetes insipidus (polyuria and polydipsia), growth delay, delayed puberty
- Systemic symptoms: fever, loss of appetite and weight loss, lethargy
Treatment Methods and Precautions
- Treatment principles: Determined according to the extent of involvement (single-system vs multisystem), whether risk organs are involved, and the severity of symptoms
- Local treatment (a single bone lesion or limited skin lesions)
- Surgical curettage or excision of the lesion
- Intralesional steroid injection
- Low-dose local radiation therapy when necessary
- Some lesions may undergo spontaneous remission with observation
- Systemic treatment (multisystem disease or risk-organ involvement, recurrent/refractory disease)
- First-line standard therapy (children): vinblastine + prednisone treatment (based on the Histiocyte Society protocol)
- For refractory or recurrent disease: other anticancer drugs such as cladribine (2‑CdA), cytarabine (ara‑C), and clofarabine
- Severe refractory/high-risk cases: hematopoietic stem cell transplantation may be considered
- Symptomatic treatment by symptom
- Central diabetes insipidus: desmopressin (DDAVP)
- Skin lesions: topical steroids, moisturization, and systemic treatment when necessary
- Lung lesions: smoking cessation (adults), consideration of oxygen therapy and systemic treatment
- Complication management and follow-up
- Follow-up and treatment for endocrine issues (growth, secondary sexual characteristics, thyroid, etc.)
- Fracture/pain management and rehabilitation therapy
- Infection prevention (caution during immunosuppression from anticancer treatment) — avoid live vaccines
- Precautions (including self-care)
- Seek medical attention immediately if signs of infection (fever, chills, etc.) occur during anticancer treatment
- Report immediately if there are signs of abnormal organ function (liver, spleen, or bone marrow)
- Hormonal abnormalities (polyuria, polydipsia, slowed growth, etc.) require early endocrine evaluation
- Fertility preservation counseling (before anticancer treatment in adolescents and adults)
Checklist Before an Outpatient Visit (Examples of Items to Bring and Records to Prepare)
- Documents/materials to bring
- Previous test results: biopsy pathology report, immunohistochemistry (IHC) results (e.g., CD1a, langerin), previous X-ray/CT/MRI/bone scans
- Medication list (prescription drugs, OTC medications, herbal medicines, etc.) and allergy history
- Recent vaccination history
- Information the patient (or caregiver) should record in advance
- Symptom records: location and intensity of pain (pain diary), frequency/pattern of fever, gastrointestinal symptoms (diarrhea), shortness of breath, photos of skin lesions (to track changes)
- Urine output and fluid intake (if diabetes insipidus is suspected, daily urine volume and whether nocturia occurs)
- Growth chart (children), pubertal development status
- Previous treatment and response (which medications or surgeries were used and how effective they were)
- Tests to request at the outpatient visit (if necessary)
- Blood tests (complete blood count, liver and kidney function, electrolytes, albumin)
- Urinalysis (urine specific gravity, urine output records)
- Imaging: X-ray, CT, MRI, or bone scan according to the lesion location
- Bone marrow examination or additional biopsy when necessary
Examples of General Questions to Ask the Doctor
- What is the goal of this treatment (cure vs remission vs symptom control)?
- What is the expected duration of the recommended treatment, and what are its major side effects?
- What are the recurrence rate and the long-term prognosis (long-term effects on growth, endocrine function, hearing, etc.)?
- What guidance is available for vaccination, infection prevention, and daily activities such as school or childcare during anticancer treatment?
- How will follow-up for growth and endocrine abnormalities or fertility issues be conducted?
Examples of Disease-Specific Questions
- In my (the patient’s) case, is this single-system disease (e.g., one bone) or multisystem disease, and how was involvement of the risk organs (liver, spleen, and bone marrow) evaluated? How will these results affect the treatment plan?
- Polyuria and polydipsia (diabetes insipidus) have developed. Is this permanent, and how long and in what manner should desmopressin treatment be continued?