ORPHA:492
Proliferating trichilemmal cyst
Publications
626
76th percentile
Trials
0
Interventional, condition-specific
Researchers
899
Distinct authors in sample
Gene link
—
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A rare large, multinodular, usually benign, tumor that is generally located in the posterior part of the scalp in aged women (over 50 years). It first appears as a painless nodule that later grows into a solid or partially cystic tumor that is mobile over the underlying subcutaneous tissues. It can present ulceration, inflammation or even bleeding and can cause necrosis of the adjacent tissues.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0018850
- UMLS:C2959585
- NCIT:C27125
Additional Mondo synonyms (9)
Pilar cyst · Pilar tumor · Pilar tumour · proliferating Pilar tumor · proliferating Pilar tumour · proliferating Tricholemmal tumor · proliferating Tricholemmal tumour · proliferating trichilemmal tumor · proliferating trichilemmal tumour
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
Research-stage checklist from open sources (GenCC, literature, Monarch when enriched, ClinicalTrials.gov). Not a prognosis or care recommendation.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
626 matched papers (303 in last 10 years) Source
- Phenotype characterisedPresent
3 HPO annotations (e.g. Sparse scalp hair; Epidermoid cyst; Skin ulcer) Source
- Animal modelNot found
No Alliance genotype “model of” associations via Monarch for these Mondo IDs
- Orphan designationNot found
No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source
- Interventional trialNot found
No matched interventional trial under our ClinicalTrials.gov rules
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)
3
Associated phenotypes · MONDO:0018850
- Sparse scalp hair
- Epidermoid cyst
- Skin ulcer
Animal models (Monarch / Alliance)
None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.
Monarch fetch 2026-07-29
Therapies
Designations, candidates, and chemicals
FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.
Orphan designation (FDA · EMA)
No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.
Open Targets candidates
No drugs or clinical candidates returned for this Mondo ID on Open Targets.
CTD chemicals (MyDisease.info)
No CTD chemical associations returned for this Mondo ID.
Literature
Is anyone studying this?
626
626 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.
626 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).
303 in the last 10 years · high confidence · 76th percentile (publications denominator)
Phrase hits: 626 · MeSH hits: 0
Who's working on it?
899
Distinct author names in 200 sampled papers — named people below.
Who's working on it?
No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.
- 01Nijhawan RI4 papers · 2026
Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, Texas. Electronic address: rajiv.nijhawan@utsouthwestern.edu.
Papers in Europe PMC - 02Zhang G4 papers · 2025
Department of Medical Ultrasound, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai 200040, China.
Papers in Europe PMC - 03Chughtai A3 papers · 2023
Histopathology, Chughtai Institute of Pathology, Lahore, PAK.
Papers in Europe PMC - 04Hoang MP3 papers · 2025
Professor of Pathology, Department of Pathology, Harvard Medical School, Massachusetts General Hospital, Boston, MA.
Papers in Europe PMC - 05Li Y3 papers · 2026
Pathology, LSU Health Shreveport, Shreveport, Louisiana, USA.
Papers in Europe PMC - 06Liao C3 papers · 2025
Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, China.
Papers in Europe PMC - 07Wang X3 papers · 2026
Department of Laboratory Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
Papers in Europe PMC - 08Wu M3 papers · 2025
Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, China.
Papers in Europe PMC - 09Abdelhammed MH2 papers · 2026
Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA.
Papers in Europe PMC - 10Agarwal S2 papers · 2023
Department of Pathology, All India Institute of Medical Sciences, New Delhi, India.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
0
interventional trials for this specific condition
No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present).
Data as of 11 September 2026 · last trial check 11 September 2026
No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.
high confidence · 38.6th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.
See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
Other registries (secondary)
Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.
raw 1 · after dedupe 1 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 1 · dropped 0 · fetched 2026-07-29
Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri
No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).
Uncertain / not reviewed (1)
Where to find support
Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.
Orphanet entry for Proliferating trichilemmal cyst — check Associations / patient organisations on that page.
India — NPRD
Last verified 2026-07-26This 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.
"Proliferating trichilemmal cyst" OR "Pilar cyst" OR "Pilar tumor" OR "Pilar tumour" OR "proliferating Pilar tumor" OR "proliferating Pilar tumour" OR "proliferating Tricholemmal tumor" OR "proliferating Tricholemmal tumour" OR "proliferating trichilemmal tumor" OR "proliferating trichilemmal tumour"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Proliferating trichilemmal cyst" OR "Pilar cyst" OR "Pilar tumor" OR "Pilar tumour" OR "proliferating Pilar tumor" OR "proliferating Pilar tumour" OR "proliferating Tricholemmal tumor" OR "proliferating Tricholemmal tumour" OR "proliferating trichilemmal tumor" OR "proliferating trichilemmal tumour"
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: ok — strategies attempted: phrase; with hits: phrase
Run this search on ClinicalTrials.gov
Confidence reasoning
- Preferred label is multi-word and distinctive
- No synonyms dropped by stoplist
- No label/synonym collisions with other diseases in this corpus
Ingested 2026-07-26T14:01:36.095Z