Skin nonmelanocytic tumor

Cysts

Vellus hair cyst



Last author update: 1 January 2015
Last staff update: 1 November 2023

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PubMed Search: Vellus hair cyst [title]

Ghassan A. Tranesh, M.D.
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Cite this page: Tranesh G. Vellus hair cyst. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumornonmelanocyticvelloushaircyst.html. Accessed March 29th, 2024.
Definition / general
  • Originally reported in children and young adults
  • No gender or racial predilection
Epidemiology
  • Occasionally associated with renal failure or various genodermatoses, including pachyonychia congenita, anhidrotic ectodermal dysplasia, hidrotic ectodermal dysplasia
  • Rarely associated with Lowe syndrome, an oculocerebrorenal syndrome characterized by Fanconi-type renal failure, intellectual disabilities, ocular abnormalities
  • Cases may be inherited (autosomal dominant), which may be manifest at birth, and is more likely to show cysts on extensor aspects of limbs
Sites
  • Small, multiple cysts over chest wall and extremities
Pathophysiology
  • Eruptive vellus hair cysts probably develop due to occlusion of the infundibulum of vellus hairs with resultant cystic dilatation and retention of keratinous debris and vellus hairs
  • The primary cause of the obstruction is unknown
  • They may also represent follicular hamartomas
Clinical features
  • Patients present with numerous asymptomatic, discrete, soft, flesh-colored or reddish-brown papules, 1 - 5 mm across, particularly over the parasternal area, although the distribution may be quite widespread
Case reports
Treatment
  • Local surgery
Clinical images

Images hosted on other servers:
Yellowish, dome shaped papules

Yellowish, dome shaped papules

Hyperpigmented follicular papules

Hyperpigmented follicular papules

Microscopic (histologic) description
  • Mid-dermal cyst containing laminated keratin and many vellus hairs
  • Epithelial lining consists of several layers of squamous epithelium, often with a granular cell layer
Microscopic (histologic) images

Images hosted on other servers:
Acanthotic epidermis

Acanthotic epidermis

Dermal cyst

Dermal cyst

Laminated keratinous material

Laminated keratinous material

Differential diagnosis
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