Dermal cysts
Dermal cysts are common in dermatopathology. Dermatopathologists can diagnose 'em.
Cysts
Common types:[1]
- Epidermal cyst (sebaceous cyst) -- most common.
- Pilar (trichilemmal) cyst.
- Dermoid cyst.
- Ganglion cyst.
- Milicem.
Epidermal necrosis
- This may be cystic. It is covered in the epidermal necrosis article, which covers erythema multiforme, Steven-Johnson syndrome and toxic epidermal necrolysis.
Venous lake
General
- Dilated vein.
Microscopic
Features:[2]
- Lined by endothelium.
- Blood in lumen.
- +/-Fibrin in lumen.
DDx:
- Angiokeratoma.
- Ectatic superficial dermal vessels.
- Irregular acanthosis.
- Longer rete ridges.
Epidermal inclusion cyst
- AKA epidermal cyst.
General
- Very common.
Microscopic
Features:
- Cyst lining has a granular layer - key feature.[3]
- Trapped collagen bundles at edge of lesion with surrounded by fibroblasts.
- Keratin.
Image:
DDx:
- Pilar cyst - no granular layer.
- Eccrine hidrocystoma - eyelid lesion; same histology.[5]
- Dermoid cyst - has adnexal structures, i.e. hair follicle, sebaceous glands, sweat glands.
- Dermatofibrosarcoma protuberans - if lesion is large.
Pilar cyst
- AKA trichilemmal cyst.
General
- Very common.
Gross
- Classic location: head ~90%.[6]
Microscopic
Features:
- Keratin.
- Cyst lining has no granular layer - key feature.
- Trapped collagen bundles at edge of lesion with surrounded by fibroblasts.
DDx:
- Epidermal cyst - has a granular layer.
Images:
- www:
- WC:
Steatocystoma
General
- Benign.
- Typically adults.
- Usually on the trunk.
- May be genetic; known as steatocystoma multiplex.[7]
- Classically autosomal dominant.[8]
Microscopic
Features:[9]
- Cyst lined by squamous epithelium with:
- Corrugated eosinophilic lining - key feature.
- Similar appearance to compact keratin (hyperkeratosis).
- Described as a hyaline cuticle.[10]
- No granular cell layer.
- Corrugated eosinophilic lining - key feature.
Images:
- Steatocystoma - low mag. (flickr.com).
- Steatocystoma - high mag. (flickr.com).
- Steatocystoma (upmc.edu).[11]
- Steatocystoma (WC).
Dermoid cyst
General
- Benign.
- Congenital choristomas.[12]
- May be found in the ovary.
Microscopic
- Cyst lined by normal (keratinized) skin with adnexal structure (hair follicles, sweat glands, sebaceous glands).
DDx:
- Epidermal cyst - no adnexal structures.
Images:
Digital mucous cyst
General
- Dome-shaped papule.
Microscopic
Features:[14]
- Mucous in superficial dermis - key feature.
- No epithelial lining; it is a pseudocyst.
Note:
- Mucin = glycolated proteins; may be part of mucous.
- Mucous = slippery secretion.
DDx:
Images:
See also
References
- ↑ TN07 D5
- ↑ Weedon's Skin Pathology. 3rd Ed. P.895.
- ↑ URL: http://emedicine.medscape.com/article/1058907-diagnosis. Accessed on: 18 March 2011.
- ↑ Crystal, P.; Shaco-Levy, R. (Mar 2005). "Concentric rings within a breast mass on sonography: lamellated keratin in an epidermal inclusion cyst.". AJR Am J Roentgenol 184 (3 Suppl): S47-8. PMID 15728019.
- ↑ Adams, SP. (Feb 1999). "Dermacase. Eccrine hydrocystoma.". Can Fam Physician 45: 297, 306. PMC 2328272. PMID 10065300. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2328272/.
- ↑ URL: http://emedicine.medscape.com/article/1058907-overview. Accessed on: 15 April 2012.
- ↑ Online 'Mendelian Inheritance in Man' (OMIM) 184500
- ↑ URL: http://path.upmc.edu/cases/case674/dx.html. Accessed on: 29 January 2012.
- ↑ Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 312. ISBN 978-0443066542.
- ↑ URL: http://path.upmc.edu/cases/case674/dx.html. Accessed on: 29 January 2012.
- ↑ URL: http://path.upmc.edu/cases/case674.html. Accessed on: 29 January 2012.
- ↑ 12.0 12.1 12.2 Gandhi N, Syed NA, Alen R. Dermoid Cyst. EyeRounds.org. posted July 26, 2010; Available from: http://www.EyeRounds.org/cases/115-dermoid-cyst.htm. Accessed on: 22 September 2011.
- ↑ Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 596. ISBN 978-1416054542.
- ↑ 14.0 14.1 URL: http://www.dermpedia.org/dermpedia-textbook/digital-mucous-myxoid-cyst. Accessed on: 17 January 2012.
- ↑ URL: http://dictionary.reference.com/browse/mucous. Accessed on: 8 January 2012.
- ↑ URL: http://dictionary.reference.com/browse/mucus. Accessed on: 8 January 2012.