Difference between revisions of "Dermal cysts"

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'''Dermal cysts''' are common in [[dermatopathology]].  Dermatopathologists can diagnose 'em.
'''Dermal cysts''', also '''skin cysts''', are common in [[dermatopathology]].  Dermatopathologists can diagnose 'em.


==Cysts==
=Overview=
Common types:<ref>TN07 D5</ref>
Common types:<ref name=Ref_TN2007_D5>{{Ref TN2007| D5}}</ref>
*[[Epidermal cyst]] (sebaceous cyst) -- most common.
*[[Epidermal cyst]] (sebaceous cyst) -- most common.
*[[pilar cyst|Pilar (trichilemmal) cyst]].
*[[pilar cyst|Pilar (trichilemmal) cyst]].
*Dermoid cyst.
*[[Dermoid cyst]].
*Ganglion cyst.
*[[Ganglion cyst]].
*Milicem.
*Milicem.


==EM, SJS, TEN==
==Epidermal necrosis==
*SJS and TEN are on a spectrum, EM is considered separate.
*This may be cystic.  It is covered in the ''[[epidermal necrosis]]'' article, which covers [[erythema multiforme]], [[Steven-Johnson syndrome]] and [[toxic epidermal necrolysis]].
 
===Erythema multiforme===
*Abbreviated ''EM''.
====General====
Features:<ref name=Ref_PBoD8_1189>{{Ref PBoD8|1189}}</ref>
*Hypersensitivity disorder to a drug or infections.
**Associated with the following: [[HSV]], Mycoplasma, Histoplasma, others.
 
Clinical:
*Target-like lesion.
 
====Microscopic====
Features:<ref name=Ref_PBoD8_1189>{{Ref PBoD8|1189}}</ref>
*Lymphocytic interface dermatitis (lymphocytes at the dermal-epidermal junction).
*Necrotic/degenerative keratinocytes - '''key feature'''.
*+/-Epidermal blistering.
*+/-Epidermal sloughing.
 
===Stevens-Johnson Syndrome===
*Abbreviated SJS.
 
Rx causes of SJS:
*NSAIDs.
*Anticonvulsants.
*Sulfonamides.
*Penicillins.
 
===Toxic Epidermal Necrolysis===
*Abbreviated TEN.
 
TEN more severe form SJS.
 
Definition:
*>30% sheet-like epidermal detachment, diffuse erythema, severe mucous membrane involvement.
*Most TEN (80%) Rx-related, only 50% of SJS Rx-related.


=Common cysts=
==Venous lake==
==Venous lake==
*Dilated vein.
{{Main|Venous lake}}


===Microscopic===
==Epidermal inclusion cyst==
Features:<ref>Weedon's Skin Pathology. 3rd Ed. P.895.</ref>
{{Main|Epidermal inclusion cyst}}
*Lined by endothelium.
*Blood in lumen.
*+/-Fibrin in lumen.


DDx:
==Pilar cyst==
*[[Angiokeratoma]].
*[[AKA]] ''trichilemmal cyst''.
**Ectatic superficial dermal vessels.
{{Main|Pilar cyst}}
**Irregular acanthosis.
**Longer rete ridges.
 
==Neurofibromatosis (von Recklinghausen's disease)==
{{Main|Neurofibromatosis}}
===Etiology===
*Genetic - autosomal dominant disorder.
 
===Management===
*Follow for malignant transformation of [[neurofibroma]] --> neurofibrosarcoma.
 
===Treatment===
*Excise suspicious lesions & lesions that are painful.


==Collagenous fibroma==
==Dermoid cyst==
===General===
===General===
*Benign.
*Benign.
*Used to be known as ''desmoplastic fibroblastoma''.
*Congenital [[choristoma]]s.<ref name=dc_uiowa>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 http://www.EyeRounds.org/cases/115-dermoid-cyst.htm].  Accessed on: 22 September 2011.</ref>
*May be found in the [[ovary]].


Epidemiology:
*May be on the lip.
===Microscopic===
===Microscopic===
Features:<ref>URL: [http://www.dermatologyoutlines.com/dermskintumornonmelanocytic.html#collagenousfibroma http://www.dermatologyoutlines.com/dermskintumornonmelanocytic.html#collagenousfibroma]. Accessed on: 19 March</ref><ref name=Ref_Sternberg4_161>{{Ref Sternberg4|161}}</ref>
Features:<ref name=dc_uiowa>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 http://www.EyeRounds.org/cases/115-dermoid-cyst.htm]. Accessed on: 22 September 2011.</ref><ref name=Ref_PCPBoD8_596>{{Ref PCPBoD8|596}}</ref>
*Acellular stroma with abundant collagen.
*Cyst lined by normal (keratinized) skin with adnexal structure (hair follicles, sweat glands, sebaceous glands).


Notes:
DDx:
*'''No''' nuclear atypia.
*[[Epidermal cyst]] - no adnexal structures.


==Dermatomyositis==
Images:
:See: ''[[Neuromuscular_pathology#Dermatomyositis]]''.
*[http://webeye.ophth.uiowa.edu/eyeforum/cases-i/case115/larger/Figure3.jpg Dermoid cyst - low mag. (uiowa.edu)].<ref name=dc_uiowa>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 http://www.EyeRounds.org/cases/115-dermoid-cyst.htm]. Accessed on: 22 September 2011.</ref>
===Gross===
*[http://webeye.ophth.uiowa.edu/eyeforum/cases-i/case115/larger/Figure4.jpg Dermoid cyst - intermed. mag. (uiowa.edu)].
*Have lesions on the knuckle - Gottron's papulle


===Microsopic===
===Sign out===
Features:
<pre>
*Lymphocytic interface dermatitis (inflammation at the dermal-epidermal junction).
SKIN CYST, RIGHT LATERAL ORBIT, EXCISION:
*Loss of rete ridges.
- DERMOID CYST
- NEGATIVE FOR MALIGNANCY.
</pre>


==Systemic lupus erythematosus==
==Pilonidal cyst==
*Lymphocytic interface dermatitis.<ref>JAH. 20 February 2009.</ref>
*[[AKA]] ''pilonidal sinus''.
*Basal layer vacuolation.<ref name=pmid18384217>{{cite journal |author=Crowson AN, Magro CM, Mihm MC |title=Interface dermatitis |journal=Arch. Pathol. Lab. Med. |volume=132 |issue=4 |pages=652–66 |year=2008 |month=April |pmid=18384217 |doi= |url=http://www.archivesofpathology.org/doi/full/10.1043/1543-2165%282008%29132%5B652%3AID%5D2.0.CO%3B2}}</ref>
*[[AKA]] ''pilonidal disease''.<ref>URL: [http://emedicine.medscape.com/article/788127-overview http://emedicine.medscape.com/article/788127-overview]. Accessed on: 10 September 2012.</ref>
{{Main|Pilonidal sinus}}


==Familial benign pemphigus==
=Less common=
*AKA ''Hailey-Hailey disease''. Was described by two brothers - that's why it is ''Hailey-Hailey''.<ref name=emed_hailey>[http://emedicine.medscape.com/article/1063224-overview http://emedicine.medscape.com/article/1063224-overview]</ref>
==Steatocystoma==
{{Main|Steatocystoma}}


===Etiology===
==Digital mucous cyst==
*Autosomal dominant with incomplete penetration.<ref name=emed_hailey/>
*[[AKA]] ''digital synovial cyst''.<ref name=dermpedia>URL: [http://www.dermpedia.org/dermpedia-textbook/digital-mucous-myxoid-cyst http://www.dermpedia.org/dermpedia-textbook/digital-mucous-myxoid-cyst]. Accessed on: 17 January 2012.</ref>
*Desmosomal defect - due to mutation in the gene ''ATP2C1''.<ref name=emed_hailey/>
*[[AKA]] ''digital myxoid pseudocyst''.<ref name=dermpedia/>
===General===
*Dome-shaped [[papule]].


===Clinical===
===Microscopic===
*Chest.
Features:<ref name=dermpedia>URL: [http://www.dermpedia.org/dermpedia-textbook/digital-mucous-myxoid-cyst http://www.dermpedia.org/dermpedia-textbook/digital-mucous-myxoid-cyst]. Accessed on: 17 January 2012.</ref>
*Intriginous regions (?sp).
*Mucous in superficial dermis - '''key feature'''.
*Typically presents individual in their 30s and 40s.<ref name=emed_hailey/>
*No epithelial lining; it is a pseudocyst.


===Histology===
Note:
*Hair folicles spared.
*Mucin = glycolated proteins; may be part of mucous.
*Epidermis thickened.
*Mucous = slippery secretion.
**Some split hairs over the "u" - "mucus" vs. "mucous".<ref>URL: [http://dictionary.reference.com/browse/mucous http://dictionary.reference.com/browse/mucous]. Accessed on: 8 January 2012.</ref><ref>URL: [http://dictionary.reference.com/browse/mucus http://dictionary.reference.com/browse/mucus]. Accessed on: 8 January 2012.</ref>


===DDx===
DDx:
*May resemble pemphigus vulgaris.
*[[Focal cutaneous mucinosis]].
*[[Ganglion cyst]].


==Epidermal inclusion cyst==
Images:
*[[AKA]] ''epidermal cyst''.
*[http://www.dermpedia.org/files/images/Digital_mucous_cyst_2.jpg Digital mucous cyst (dermpedia.org)].<ref name=dermpedia>URL: [http://www.dermpedia.org/dermpedia-textbook/digital-mucous-myxoid-cyst http://www.dermpedia.org/dermpedia-textbook/digital-mucous-myxoid-cyst]. Accessed on: 17 January 2012.</ref>
===General===
*[http://www.dermpedia.org/files/images/Untitled89.jpg Digital mucous cyst (dermpedia.org)].<ref>URL: [http://www.dermpedia.org/case/digital-mucous-cyst-ganglion-type http://www.dermpedia.org/case/digital-mucous-cyst-ganglion-type]. Accessed on: 5 July 2013.</ref>
*Very common.


===Microscopic===
===Sign out===
Features:
<pre>
*Cyst lining has a granular layer - '''key feature'''.<ref>URL: [http://emedicine.medscape.com/article/1058907-diagnosis http://emedicine.medscape.com/article/1058907-diagnosis]. Accessed on: 18 March 2011.</ref>  
LESION, LEFT INDEX FINGER, EXCISION:
*Trapped collagen bundles at edge of lesion with surrounded by fibroblasts.
- DIGITAL MUCOUS CYST.
*Keratin.
</pre>


Image:
==Apocrine cystadenoma==
*[http://missinglink.ucsf.edu/lm/DermatologyGlossary/img/Dermatology%20Glossary/Glossary%20Histo%20Images/epidermal_follicular_cyst.jpg Epidermal follicular cyst (ucsf.edu)].
 
DDx:
*[[Dermatofibrosarcoma]] - if lesion is large.
*[[Pilar cyst]] - no granular layer.
 
==Pilar cyst==
*[[AKA]] trichilemmal cyst.
===General===
===General===
*Very common.
*Uncommon.


===Microscopic===
===Microscopic===
Features:
Features:<ref name=Ref_Derm316>{{Ref Derm|316}}</ref>
*Keratin.
*Multiloculated.
*Cyst lining has no granular layer - '''key feature'''.
*Apocrine differentiation: columnar epithelium +/- apical snouts.
*Trapped collagen bundles at edge of lesion with surrounded by fibroblasts.
*Solid areas of epithelial proliferation.
*Papillary projections into the cyst.


DDx:  
Images:
*[[Epidermal cyst]] - has a granular layer.
*[http://alf3.urz.unibas.ch/pathopic/e/getpic-fra.cfm?id=7292 Apocrine cystadenoma (unibas.ch)].
*[http://www.flickr.com/photos/40764007@N08/6499470691/ Apocrine cystadenoma (flickr.com)].


==See also==
=See also=
*[[Non-malignant skin disease]]
*[[Non-malignant skin disease]]
*[[Dermatopathology introduction]]
*[[Dermatopathology introduction]]


==References==
=References=
{{reflist|2}}
{{reflist|2}}


[[Category:Non-malignant skin disease]]
[[Category:Non-malignant skin disease]]
[[Category:Dermatopathology]]
[[Category:Dermatopathology]]

Latest revision as of 17:22, 26 August 2016

Dermal cysts, also skin cysts, are common in dermatopathology. Dermatopathologists can diagnose 'em.

Overview

Common types:[1]

Epidermal necrosis

Common cysts

Venous lake

Epidermal inclusion cyst

Pilar cyst

  • AKA trichilemmal cyst.

Dermoid cyst

General

Microscopic

Features:[2][3]

  • Cyst lined by normal (keratinized) skin with adnexal structure (hair follicles, sweat glands, sebaceous glands).

DDx:

Images:

Sign out

SKIN CYST, RIGHT LATERAL ORBIT, EXCISION:
- DERMOID CYST
- NEGATIVE FOR MALIGNANCY.

Pilonidal cyst

  • AKA pilonidal sinus.
  • AKA pilonidal disease.[4]

Less common

Steatocystoma

Digital mucous cyst

  • AKA digital synovial cyst.[5]
  • AKA digital myxoid pseudocyst.[5]

General

Microscopic

Features:[5]

  • 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.
    • Some split hairs over the "u" - "mucus" vs. "mucous".[6][7]

DDx:

Images:

Sign out

LESION, LEFT INDEX FINGER, EXCISION:
- DIGITAL MUCOUS CYST.

Apocrine cystadenoma

General

  • Uncommon.

Microscopic

Features:[9]

  • Multiloculated.
  • Apocrine differentiation: columnar epithelium +/- apical snouts.
  • Solid areas of epithelial proliferation.
  • Papillary projections into the cyst.

Images:

See also

References

  1. Greenwald, J.; Heng, M. (2007). Toronto Notes for Medical Students 2007 (2007 ed.). The Toronto Notes Inc. for Medical Students Inc.. pp. D5. ISBN 978-0968592878.
  2. 2.0 2.1 2.2 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.
  3. 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.
  4. URL: http://emedicine.medscape.com/article/788127-overview. Accessed on: 10 September 2012.
  5. 5.0 5.1 5.2 5.3 URL: http://www.dermpedia.org/dermpedia-textbook/digital-mucous-myxoid-cyst. Accessed on: 17 January 2012.
  6. URL: http://dictionary.reference.com/browse/mucous. Accessed on: 8 January 2012.
  7. URL: http://dictionary.reference.com/browse/mucus. Accessed on: 8 January 2012.
  8. URL: http://www.dermpedia.org/case/digital-mucous-cyst-ganglion-type. Accessed on: 5 July 2013.
  9. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 316. ISBN 978-0443066542.