ULTRA-RARE CANCERHistiocytic DisorderWHO 5th Edition Classification

Erdheim-Chester Disease (ECD)

Ultra-Rare Malignancy (< 1 case per 1,000,000 / year) • Clinical Staging, Genomic Targets & Vetted Specialists

A rare histiocytic neoplasm in which foamy, lipid-laden histiocytes infiltrate bone, the tissue around the kidneys, the aorta, the heart, the pituitary and the brain. It was long thought to be an inflammatory condition; the discovery that around half of cases carry BRAF V600E reclassified it as a clonal neoplasm and transformed its treatment.

Request Rare Cancer Tumor Board Find NCI Treatment CentersAsk Vani AI Navigator

Emergent Referral AdvisoryImmediate Action

Certain rare malignancies progress rapidly or carry acute risk of airway obstruction, acute spinal compression, hydrocephalus, or biopsy-seeding. Do not perform needle biopsy or surgery outside of an NCI-designated specialty sarcoma or neuro-oncology unit without multidisciplinary tumor board review.

Report immediately to an emergency department or tertiary oncologist upon:

  • Symmetric sclerosis of the long bones on imaging
  • Perinephric infiltration ('hairy kidney') or circumferential aortic sheathing
Who It Affects

Adults, typically 40-70 years; male predominance

Annual Incidence

Fewer than 1 per million; roughly 1,500 cases reported worldwide

Clinical Evidence Review

Last audited: 2026-08-13 against NCCN, ESMO, and WHO 5th ed. guidelines.

Clinical Presentation & Hallmark Symptoms

Presenting signs most frequently observed across clinical case series

Bone pain, characteristically in both lower legs
Excessive thirst and urination (diabetes insipidus)
Fatigue, fever and night sweats
Bulging eyes (exophthalmos) or eyelid xanthelasma
Breathlessness, kidney impairment, or neurological problems including ataxia

Genomic Profiling & Defining Molecular Lesions

Critical diagnostic fusions, somatic mutations, and therapeutic targets

Rare malignancies frequently depend on distinct oncogenic drivers rather than conventional environmental carcinogens. Comprehensive Next-Generation Sequencing (NGS comprehensive panel) and FISH/IHC are mandatory to establish the true diagnosis and screen for basket trial agents.

BRAF V600E (about 50%)MAP2K1NRASPIK3CAALK fusions - rare

Standard-of-Care Treatment Protocol

Frontline and multimodal strategies established under international consensus guidelines

1

Vemurafenib for BRAF V600E-mutated disease (regulatory-approved indication)

Administered in specialized high-volume oncology programs with subspecialty pathology and organ-preservation protocols.

2

MEK inhibition (cobimetinib) for BRAF wild-type or MAP2K1-mutated disease

Administered in specialized high-volume oncology programs with subspecialty pathology and organ-preservation protocols.

3

Interferon-alpha / pegylated interferon as an older first-line option

Administered in specialized high-volume oncology programs with subspecialty pathology and organ-preservation protocols.

4

Anakinra or infliximab in selected patients

Administered in specialized high-volume oncology programs with subspecialty pathology and organ-preservation protocols.

5

Organ-specific supportive care - desmopressin, cardiac and renal management

Administered in specialized high-volume oncology programs with subspecialty pathology and organ-preservation protocols.

Clinical Trial Advisory: For rare and ultra-rare malignancies, enrollment in an active clinical trial or expanded-access program is widely considered the preferred standard of care by ASCO and NCCN panels.

Prognosis & Disease Trajectory

Objective clinical outlook without false reassurance

Historically poor with cardiac or central nervous system involvement, but substantially improved by MAPK-targeted therapy. Many patients now achieve durable disease control; central nervous system involvement remains the strongest adverse prognostic factor.

Note: Statistics reflect cohort averages. Individual outcomes depend heavily on performance status, resectability, biomarker expression, and timely access to specialized tertiary care.

Active Research, Biomarkers & Clinical Trials

Novel investigational agents, phase I/II trials, and international rare disease consortia

Cobimetinib has demonstrated activity across histiocytic neoplasms regardless of mutation, and pan-histiocytosis basket trials are the main route to new agents.

Need Help Matching to an Active Rare Cancer Trial?

ByOnco scans ClinicalTrials.gov, NCI trial networks, and institutional registries for open patient cohorts.

Request Trial Match
Expert Clinicians

Verified Specialists for Erdheim-Chester Disease

Browse All Oncologists

Dr. Eli L. Diamond

Neuro-oncologist

10+ yrs exp

MSKCC

New York, USA

Erdheim-Chester DiseaseHistiocytic DisordersClinical Trials
Vetted DirectoryConsult Specialist

Dr. Chng Wee Joo

Senior Hematologist

40+ yrs exp

NUH

Singapore, Singapore

HematologyHistiocytic DisordersECD
Vetted DirectoryConsult Specialist

Dr. Julien Haroche

Internist

20+ yrs exp

Pitié-Salpêtrière Hospital

Paris, France

Erdheim-Chester DiseaseHistiocytic NeoplasmsTargeted Therapies
Vetted DirectoryConsult Specialist

Dr. Sameer Rastogi

Sarcoma Medical Oncologist

15+ yrs exp

AIIMS, New Delhi

New Delhi, India

Rare HistiocytosesECDTargeted Therapies
Vetted DirectoryConsult Specialist
Hospital Network

Designated Cancer Centers with Dedicated Programs

Search All 72 NCI Centers

Memorial Sloan Kettering Cancer Center

NY

NCI-Designated Comprehensive Cancer Center

World-leading rare tumor board & pediatric solid tumor protocols

Proton TherapyCAR-T Cell TherapyRobotic Surgery
1,000+ Active Clinical TrialsView Center Profile

University of Texas MD Anderson Cancer Center

TX

NCI-Designated Comprehensive Cancer Center

Largest specialized rare cancer and sarcoma multidisciplinary program

Proton TherapyCAR-T Cell TherapyCyberKnife SBRT
1,200+ Active Clinical TrialsView Center Profile

Dana-Farber / Harvard Cancer Center

MA

NCI-Designated Comprehensive Cancer Center

Pioneering genomic molecular tumor boards & rare histologies

Proton TherapyCAR-T Cell TherapyPhase I Unit
1,100+ Active Clinical TrialsView Center Profile

Mayo Clinic Comprehensive Cancer Center

MN

NCI-Designated Comprehensive Cancer Center

High-volume surgical oncology & rare endocrine/neuroendocrine expertise

Proton TherapyCAR-T Cell TherapyCyberKnife SBRT
600+ Active Clinical TrialsView Center Profile

Frequently Asked Clinical Questions

Authoritative guidance on diagnosis, tumor boards, genomic markers, and care options

Related Rare Malignancies in Catalog

ultra-rare

Malignant Rhabdoid Tumor

ultra-rare

Hepatosplenic T-cell Lymphoma (HSTCL)

ultra-rare

T-cell Prolymphocytic Leukemia (T-PLL)

ultra-rare

Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN)

Independent Tumor Board Review

Facing a Diagnosis of Erdheim-Chester Disease?

Rare cancers demand rare expertise. Connect your medical records to US NCI-fellowship trained oncologists, subspecialist pathologists, and active clinical trial investigators within 12 to 72 hours.

Upload Scans for Second Opinion Schedule Virtual Teleconsult