Difference between revisions of "Dermal cysts"

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'''Dermal cysts''', also '''skin 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 name=Ref_TN2007_D5>{{Ref TN2007| 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.
Line 12: Line 12:
*This may be cystic.  It is covered in the ''[[epidermal necrosis]]'' article, which covers [[erythema multiforme]], [[Steven-Johnson syndrome]] and [[toxic epidermal necrolysis]].
*This may be cystic.  It is covered in the ''[[epidermal necrosis]]'' article, which covers [[erythema multiforme]], [[Steven-Johnson syndrome]] and [[toxic epidermal necrolysis]].


=Common cysts=
==Venous lake==
==Venous lake==
===General===
{{Main|Venous lake}}
*Dilated vein.
 
Clinical:
*Blanch with pressure.<ref>URL: [http://dermatlas.med.jhmi.edu/derm/IndexDisplay.cfm?ImageID=-969536424 http://dermatlas.med.jhmi.edu/derm/IndexDisplay.cfm?ImageID=-969536424]. Accessed on: 13 August 2012.</ref>
 
===Gross===
*Purple/blue spot.
 
Images:
*[http://dermatlas.med.jhmi.edu/derm/IndexDisplay.cfm?ImageID=-969536424 Venous lake (jhmi.edu)].<ref name=jhmi_vl>URL: [http://dermatlas.med.jhmi.edu/derm/result.cfm?Diagnosis=605386295 http://dermatlas.med.jhmi.edu/derm/result.cfm?Diagnosis=605386295]. Accessed on: 13 August 2012.</ref>
*[http://dermatlas.med.jhmi.edu/derm/IndexDisplay.cfm?ImageID=-881531868 Venous lake (jhmi.edu)].<ref name=jhmi_vl>URL: [http://dermatlas.med.jhmi.edu/derm/result.cfm?Diagnosis=605386295 http://dermatlas.med.jhmi.edu/derm/result.cfm?Diagnosis=605386295]. Accessed on: 13 August 2012.</ref>
 
===Microscopic===
Features:<ref>Weedon's Skin Pathology. 3rd Ed. P.895.</ref>
*Lined by endothelium.
*Blood in lumen.
*+/-Fibrin in lumen.
*+/-[[Solar elastosis]] - very common.<ref name=Ref_Derm551>{{Ref Derm|551}}</ref>
 
DDx:
*[[Angiokeratoma]].
**Ectatic superficial dermal vessels.
**Irregular acanthosis.
**Longer rete ridges.
*[[Cherry hemangioma]].<ref name=Ref_Derm551>{{Ref Derm|551}}</ref>
 
Images:
*[http://dermatlas.med.jhmi.edu/derm/IndexDisplay.cfm?ImageID=1982738883 Venous lake (jhmi.edu)].<ref name=jhmi_vl>URL: [http://dermatlas.med.jhmi.edu/derm/result.cfm?Diagnosis=605386295 http://dermatlas.med.jhmi.edu/derm/result.cfm?Diagnosis=605386295]. Accessed on: 13 August 2012.</ref>


==Epidermal inclusion cyst==
==Epidermal inclusion cyst==
*[[AKA]] ''epidermal cyst''.
{{Main|Epidermal inclusion cyst}}
*[[AKA]] ''epidermoid cyst''.<ref name=Ref_Derm302>{{Ref Derm|302}}</ref>
*[[AKA]] ''follicular cyst, infundibular type''.
===General===
*Very common.
*The clinical term is ''[[sebaceous cyst]]''.
**This is a misnomer as they contain keratin (not sebum).<ref name=dermis36946>URL: [http://www.dermis.net/dermisroot/en/36946/diagnose.htm http://www.dermis.net/dermisroot/en/36946/diagnose.htm]. Accessed on: 2 November 2012.</ref><ref name=pmid18201468>{{Cite journal  | last1 = Venus | first1 = MR. | last2 = Eltigani | first2 = EA. | last3 = Fagan | first3 = JM. | title = Just another sebaceous cyst? | journal = Ann R Coll Surg Engl | volume = 89 | issue = 6 | pages = W19-21 | month = Sep | year = 2007 | doi = 10.1308/147870807X227791 | PMID = 18201468 | PMC = 2121251 }}.</ref>
**The term may be used to refer to a [[pilar cyst]].
 
===Gross===
Features:<ref>URL: [http://dermatlas.med.jhmi.edu/derm/result.cfm?diagnosis=128 http://dermatlas.med.jhmi.edu/derm/result.cfm?diagnosis=128]. Accessed on: 2 November 2012.</ref>
*[[Nodule]].
*+/-Yellowish colour.
 
DDx:
*[[Pilar cyst]] - indistinguishable on gross.<ref name=dermis36946>URL: [http://www.dermis.net/dermisroot/en/36946/diagnose.htm http://www.dermis.net/dermisroot/en/36946/diagnose.htm]. Accessed on: 2 November 2012.</ref>
*[[Melanoma]].<ref name=pmid18201468/>
 
Image:
*[http://commons.wikimedia.org/wiki/File:Inflamed_epidermal_inclusion_cyst.jpg Epidermal inclusion cyst (WC)].
 
===Microscopic===
Features:
*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>
*Trapped collagen bundles at edge of lesion with surrounded by fibroblasts.
*Keratin.
*+/-[[granuloma|Granulomatous inflammation]] due to rupture.
 
Image:
*[http://www.flickr.com/photos/euthman/5517587941/in/photostream/ Epidermal inclusion cyst (flickr.com)].
*[http://www.ajronline.org/content/184/3_supp/S47/F4.expansion.html Epidermal inclusion cyst (ajronline.org)].<ref name=pmid15728019>{{Cite journal  | last1 = Crystal | first1 = P. | last2 = Shaco-Levy | first2 = R. | title = Concentric rings within a breast mass on sonography: lamellated keratin in an epidermal inclusion cyst. | journal = AJR Am J Roentgenol | volume = 184 | issue = 3 Suppl | pages = S47-8 | month = Mar | year = 2005 | doi =  | PMID = 15728019 |URL = http://www.ajronline.org/cgi/pmidlookup?view=long&pmid=15728019}}</ref>
 
DDx:
*[[Pilar cyst]] - no granular layer.
*[[Eccrine hidrocystoma]] - eyelid lesion; same histology.<ref name=pmid10065300>{{Cite journal  | last1 = Adams | first1 = SP. | title = Dermacase. Eccrine hydrocystoma. | journal = Can Fam Physician | volume = 45 | issue =  | pages = 297, 306 | month = Feb | year = 1999 | doi =  | PMID = 10065300 |PMC = 2328272 }}</ref>
*[[Dermoid cyst]] - has adnexal structures, i.e. hair follicle, sebaceous glands, sweat glands.
*Cystic [[squamous cell carcinoma of the skin|squamous cell carcinoma]].<ref name=pmid12079164>{{Cite journal  | last1 = Lin | first1 = CY. | last2 = Jwo | first2 = SC. | title = Squamous cell carcinoma arising in an epidermal inclusion cyst. | journal = Chang Gung Med J | volume = 25 | issue = 4 | pages = 279-82 | month = Apr | year = 2002 | doi =  | PMID = 12079164 }}</ref>
*[[Keratoacanthoma]].<ref name=Ref_Derm302>{{Ref Derm|302}}</ref>
*[[Dermatofibrosarcoma protuberans]] - if lesion is large.
*Hybrid epidermoid and trichilemmal cyst.<ref name=pmid6643785>{{Cite journal  | last1 = Brownstein | first1 = MH. | title = Hybrid cyst: a combined epidermoid and trichilemmal cyst. | journal = J Am Acad Dermatol | volume = 9 | issue = 6 | pages = 872-5 | month = Dec | year = 1983 | doi =  | PMID = 6643785 }}</ref>
 
===Sign out===
<pre>
SKIN CYST, BACK, EXCISION:
- EPIDERMAL INCLUSION CYST.
</pre>
 
<pre>
SKIN LESION, RIGHT CHEEK, EXCISION:
- RUPTURED EPIDERMAL INCLUSION CYST.
</pre>
 
====Micro====
The sections show hair-bearing skin with a cyst that is lined by squamous epithelium with a granular layer.  The cyst contains keratin. The overlying epithelium is unremarkable.
 
=====Ruptured=====
The section shows a dermal collection of neutrophils with acellular keratin-like material surrounded by histiocytes and fibrosis.  The lesion is completely excised in the plane of section.  Hair follicles are adjacent to the abscess; however, they are not inflamed.


==Pilar cyst==
==Pilar cyst==
*[[AKA]] ''trichilemmal cyst''.
*[[AKA]] ''trichilemmal cyst''.
===General===
{{Main|Pilar cyst}}
*Very common.
 
===Gross===
*Classic location: head ~90%.<ref>URL: [http://emedicine.medscape.com/article/1058907-overview http://emedicine.medscape.com/article/1058907-overview]. Accessed on: 15 April 2012.</ref>
 
===Microscopic===
Features:<ref name=Ref_Derm309>{{Ref Derm|309}}</ref>
*Keratin.
*Cyst lining:
**Has no granular layer - '''key feature'''.
***Keratohyaline granules (as seen in the granular layer) may be seen focally.
**Inner most cyst lining cells are large cells with abundant eosinophilic cytoplasm.
 
DDx:
*[[Epidermal cyst]] - has a granular layer.
 
Images:
*www:
**[http://dermatlas.med.jhmi.edu/derm/indexDisplay.cfm?ImageID=69966366 Trichilemmal cyst (dermatlas.med.jhmi.edu)].
**[http://www.flickr.com/photos/40764007@N08/3881846034/in/photostream/ Trichilemmal cyst (flickr.com)].
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Trichilemmal_cyst_-_intermed_mag.jpg Trichilemmal cyst - intermed. mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Trichilemmal_cyst_-_very_high_mag.jpg Trichilemmal cyst - very high mag. (WC)].
 
===Sign out===
<pre>
SKIN CYST, LEFT FLANK, EXCISION:
- TRICHILEMMAL CYST (PILAR CYST).
</pre>
 
====Micro====
The sections show a cyst that is lined by squamous epithelium without a granular layer. Focally, keratohyaline granules are seen in the cyst lining cells. The innermost cyst lining cells are large and have abundant eosinophilic cytoplasm. The cyst contains keratin.
 
==Steatocystoma==
===General===
*Benign.
*Typically adults.
*Usually on the trunk.
*May be genetic; known as ''steatocystoma multiplex''.<ref name=omim184500>{{OMIM|184500}}</ref>
**Classically autosomal dominant.<ref>URL: [http://path.upmc.edu/cases/case674/dx.html http://path.upmc.edu/cases/case674/dx.html]. Accessed on: 29 January 2012.</ref>
===Microscopic===
Features:<ref name=Ref_Derm312>{{Ref Derm|312}}</ref>
*Cyst lined by squamous epithelium with:
*#Corrugated eosinophilic lining - '''key feature'''.
*#*Similar appearance to compact keratin (hyperkeratosis).
*#*Described as a ''hyaline cuticle''.<ref>URL: [http://path.upmc.edu/cases/case674/dx.html http://path.upmc.edu/cases/case674/dx.html]. Accessed on: 29 January 2012.</ref>
*#'''No''' granular cell layer.
 
Images:
*www:
**[http://www.flickr.com/photos/santoshpath/4788590105/in/photostream/ Steatocystoma - low mag. (flickr.com)].
**[http://www.flickr.com/photos/santoshpath/4788590109/ Steatocystoma - high mag. (flickr.com)].
**[http://path.upmc.edu/cases/case674/images/fig03.jpg Steatocystoma (upmc.edu)].<ref>URL: [http://path.upmc.edu/cases/case674.html http://path.upmc.edu/cases/case674.html]. Accessed on: 29 January 2012.</ref>
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:SkinTumors-P6260388.JPG Steatocystoma (WC)].
**[http://commons.wikimedia.org/wiki/File:Steatocystoma_-_low_mag.jpg Steatocystoma - low mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Steatocystoma_-_intermed_mag.jpg Steatocystoma - intermed. mag. (WC)].


==Dermoid cyst==
==Dermoid cyst==
Line 179: Line 39:
*[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>
*[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>
*[http://webeye.ophth.uiowa.edu/eyeforum/cases-i/case115/larger/Figure4.jpg Dermoid cyst - intermed. mag. (uiowa.edu)].
*[http://webeye.ophth.uiowa.edu/eyeforum/cases-i/case115/larger/Figure4.jpg Dermoid cyst - intermed. mag. (uiowa.edu)].
===Sign out===
<pre>
SKIN CYST, RIGHT LATERAL ORBIT, EXCISION:
- DERMOID CYST
- NEGATIVE FOR MALIGNANCY.
</pre>
==Pilonidal cyst==
*[[AKA]] ''pilonidal sinus''.
*[[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}}
=Less common=
==Steatocystoma==
{{Main|Steatocystoma}}


==Digital mucous cyst==
==Digital mucous cyst==
*[[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>
*[[AKA]] ''digital myxoid pseudocyst''.<ref name=dermpedia/>
===General===
===General===
*Dome-shaped [[papule]].
*Dome-shaped [[papule]].
Line 196: Line 74:
DDx:
DDx:
*[[Focal cutaneous mucinosis]].
*[[Focal cutaneous mucinosis]].
*[[Ganglion cyst]].


Images:
Images:
*[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>
*[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>
*[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>


==Pilonidal cyst==
===Sign out===
*[[AKA]] ''pilonidal sinus''.
<pre>
*[[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>
LESION, LEFT INDEX FINGER, EXCISION:
- DIGITAL MUCOUS CYST.
</pre>


==Apocrine cystadenoma==
===General===
===General===
*Benign.
*Uncommon.
*Young adults (late teens, early twenties) - usu. men.<ref>URL: [http://www.nhs.uk/conditions/Pilonidal-sinus/Pages/Introduction.aspx http://www.nhs.uk/conditions/Pilonidal-sinus/Pages/Introduction.aspx]. Accessed on: 10 September 2012.</ref>
 
===Gross===
*Usually at gluteal folds.
**Uncommon: axilla, genital region, umbilicus, scalp.<ref name=Ref_Derm326>{{Ref Derm|326}}</ref>


===Microscopic===
===Microscopic===
Features:<ref name=Ref_Derm326>{{Ref Derm|326}}</ref>
Features:<ref name=Ref_Derm316>{{Ref Derm|316}}</ref>
*Cyst or pseudocyst into the deep dermis.
*Multiloculated.
**May be lined by squamous epithelium with inflammation +/-[[pseudoepitheliomatous hyperplasia]].
*Apocrine differentiation: columnar epithelium +/- apical snouts.
*Neutrophils.
*Solid areas of epithelial proliferation.
*[[Granuloma|Granulomatous inflammation]].
*Papillary projections into the cyst.


DDx:
Images:
*[[Squamous cell carcinoma of the skin]] with inflammation.<ref name=pmid19482585>{{Cite journal  | last1 = Chatzis | first1 = I. | last2 = Noussios | first2 = G. | last3 = Katsourakis | first3 = A. | last4 = Chatzitheoklitos | first4 = E. | title = Squamous cell carcinoma related to long standing pilonidal-disease. | journal = Eur J Dermatol | volume = 19 | issue = 4 | pages = 408-9 | month =  | year =  | doi = 10.1684/ejd.2009.0705 | PMID = 19482585 }}</ref>
*[http://alf3.urz.unibas.ch/pathopic/e/getpic-fra.cfm?id=7292 Apocrine cystadenoma (unibas.ch)].
*Infection.
*[http://www.flickr.com/photos/40764007@N08/6499470691/ Apocrine cystadenoma (flickr.com)].
 
===Sign out===
<pre>
SKIN LESION (PILONIDAL SINUS), EXCISION:  
- PILONIDAL SINUS.
- NEGATIVE FOR MALIGNANCY.
</pre>
====Micro====
The section shows hair-bearing skin with a deep sinus tract containing large clusters of neutrophils, abundant plasma cells, hemosiderin-laden macrophages, eosinophils and multinucleated giant cells. The core of the lesion is, focally, well-vascularized. At the edge of the lesion is fibrotic tissue with plump fibroblasts.  Benign, fibrofatty tissue with scant inflammation completely surrounds the tract, in the plane of section; however, it is focally fragmented. There is no squamous lining within the sinus.  No nuclear atypia is identified.


==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.