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ORPHA:58017

Classic hairy cell leukemia

medium confidenceDisorder

Also known as: HCL-C · Leukemic reticuloendotheliosis

Publications

8,929

96.7th percentile

Trials

94

Interventional, condition-specific

Researchers

1,160

Distinct authors in sample

Gene link

—

Readiness

2/6

Stages with a signal

Clinical definition (Orphanet)

A rare, slowly , chronic leukemia characterized by presence of abnormal B-lymphocytes (medium sized with abundant irregular pale cytoplasm, hair-like cytoplasmic projections/ruffled cytoplasmic border, a round or bean-shaped nucleus and absent nucleoli) in the blood or bone marrow, spleen and peripheral blood pancytopenia, notable monocytopenia, and marked susceptibility to infection. The characteristic immunophenotype is CD11c+, CD25+, CD103+ and CD123+ with a BRAF mutation in most cases.

How rare: 1-9 / 1 000 000 — roughly one to nine people per million. In a city the size of Kolkata, perhaps a few dozen.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (3)

HCL · hairy cell leukemia · leukemic reticuloendotheliosis

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

2/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedNot found

    No GenCC disease–gene assertion in this build

  2. LiteraturePresent

    8,929 matched papers (3,625 in last 10 years) Source

  3. Phenotype characterisedNot checked

    Not yet enriched from Monarch / HPO

  4. Animal modelNot checked

    Not yet enriched from Monarch / Alliance

  5. Orphan designationNot checked

    FDA/EMA orphan-drug designation not enriched yet

  6. Interventional trialPresent

    94 matched on ClinicalTrials.gov (13 recruiting in sample)

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Not yet — the cause hasn't been pinned down in GenCC.

No strong gene–disease assertion joined for this Orphanet entity.

Phenotypes (Monarch / HPO)

Not enriched in this build — Monarch phenotype joins were not run for this record.

Animal models (Monarch / Alliance)

Not enriched in this build.

Literature

Is anyone studying this?

8,929

8,929 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.

8,929 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).

3,625 in the last 10 years · medium confidence · 96.7th percentile (publications denominator)

Phrase hits: 8,928 · MeSH hits: 10

Open Europe PMC search

Who's working on it?

1,160

Distinct author names in 200 sampled papers — named people below.

Who's working on it?

People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.

  1. 01
    Tiacci E14 papers · 2026

    Institute of Hematology, Department of Medicine and Surgery, University and Hospital of Perugia, Perugia, Italy.

    Papers in Europe PMC
  2. 02
    Troussard X13 papers · 2026

    Department of Hematology, Centre Hospitalier Universitaire Cote de Nacre, Caen, France.

    Papers in Europe PMC
  3. 03
    Falini B9 papers · 2026

    Institute of Hematology, Department of Medicine and Surgery, University and Hospital of Perugia, Perugia, Italy.

    Papers in Europe PMC
  4. 04
    Kreitman RJ9 papers · 2026

    Laboratory of Molecular Biology, National Cancer Institute, NIH, Bethesda, MD, USA.

    Papers in Europe PMC
  5. 05
    Saven A9 papers · 2026

    Division of Hematology and Oncology, Scripps Clinic, La Jolla, CA, USA.

    Papers in Europe PMC
  6. 06
    Tadmor T9 papers · 2026

    Hematology Unit, Bnai Zion Medical Center, Haifa, Israel.

    Papers in Europe PMC
  7. 07
    Andritsos LA7 papers · 2026

    The University of New Mexico Comprehensive Cancer Center, Albuquerque, NM; and.

    Papers in Europe PMC
  8. 08
    Dietrich S7 papers · 2026

    Department of Hematology, University Hospital of Heidelberg, Heidelberg, Germany.

    Papers in Europe PMC
  9. 09
    Epperla N7 papers · 2025

    Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH, USA.

    Papers in Europe PMC
  10. 10
    Gozzetti A7 papers · 2026

    Dept. of Medicine, Surgery and Neurosciences, University of Siena, Policlinico S. Maria alle Scotte-, Siena, Italy.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

94

interventional trials for this specific condition

94 interventional trials matched this specific condition name; 13 currently recruiting in our sample.

Data as of 27 July 2026

94 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 98.3th percentile).

medium confidence · 98.3th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

94 interventional trials matched after quoted-phrase search and title/condition post-filter.

Observational and natural-history studies

14 observational studies match this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.

Recruiting or not-yet-recruiting

Open the complete matched search on ClinicalTrials.gov

Where to find support

We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:

India — NPRD

Last verified 2026-07-26

This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

"Classic hairy cell leukemia" OR "HCL-C" OR "Leukemic reticuloendotheliosis" OR "hairy cell leukemia"

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Leukemia, Hairy Cell

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"Classic hairy cell leukemia" OR "HCL-C" OR "Leukemic reticuloendotheliosis" OR "hairy cell leukemia" OR "Leukemia, Hairy Cell"

Interventional trials matched via: both, phrase, mesh (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).

Study-type breakdown: 94 interventional · 14 observational · 1 expanded access. Only interventional studies enter the trial headline.

Query health: ok — strategies attempted: phrase, mesh; with hits: phrase, mesh

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: HCL

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • 1 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-27T01:00:05.970Z