Human Phenotype Ontology

Last uploaded: August 13, 2024
Preferred Name

Trichilemmal cyst
Synonyms

Pilar cyst

Definitions

Nontender, round and firm, but slightly compressible, intradermal or subcutaneous cyst measuring 0.5-5 cm in diameter. Trichilemmal cysts are acquired rather than congenital, and tend to appear on the scalp rather than the face, and to be intradermal rather than subcutaneous. Epidermal cysts and trichilemmal cysts are clinically indistinguishable. The wall of the epidermal cyst conserves the epidermal layers, but the wall of the trichilemmal cysts, which arise from the external root sheath, shows palisading of unlayered epithelial cells. Homogeneous horny material that is further degraded to fat and cholesterol forms within both types of cysts.

ID

http://purl.obolibrary.org/obo/HP_0025246

comment

Epidermal cysts and trichilemmal cysts are clinically indistinguishable. The wall of the epidermal cyst conserves the epidermal layers, but the wall of the trichilemmal cysts, which arise from the external root sheath, shows palisading of unlayered epithelial cells. Homogeneous horny material that is further degraded to fat and cholesterol forms within both types of cysts.

dc_date

2016-12-17T13:45:04Z

definition

Nontender, round and firm, but slightly compressible, intradermal or subcutaneous cyst measuring 0.5-5 cm in diameter. Trichilemmal cysts are acquired rather than congenital, and tend to appear on the scalp rather than the face, and to be intradermal rather than subcutaneous.

has_exact_synonym

Pilar cyst

has_obo_namespace

human_phenotype

id

HP:0025246

label

Trichilemmal cyst

notation

HP:0025246

prefLabel

Trichilemmal cyst

terms_creator

https://orcid.org/0000-0002-0736-9199

treeView

http://purl.obolibrary.org/obo/HP_0025245

subClassOf

http://purl.obolibrary.org/obo/HP_0025245

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