Difference between revisions of "Fungi"

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=Specific fungi=
=Specific fungi=
==Histoplasmosis==
==Histoplasmosis==
*''Histoplasma capulatum'' - primative fungus, typical location: lung.
===General===
** Often in yeast form in tissue 2-5 micrometres.<ref name=Ref_WMSP103>{{Ref WMSP|103}}</ref>  
*Organism: ''Histoplasma''.
*Specific organism: ''Histoplasma capulatum''.
*Typical location: [[lung]].
 
===Microscopic===
Features:
* Often in yeast form in tissue 2-5 micrometres.<ref name=Ref_WMSP103>{{Ref WMSP|103}}</ref>  
** Nice bright red on PAS-D - [http://en.wikipedia.org/wiki/File:Histoplasma_pas-d.jpg histoplasmosis (wikipedia.org)].
** Nice bright red on PAS-D - [http://en.wikipedia.org/wiki/File:Histoplasma_pas-d.jpg histoplasmosis (wikipedia.org)].
*** Have a "central dot"<ref>URL: [http://moon.ouhsc.edu/kfung/jty1/opaq/PathQuiz/A6I001-PQ01-M.htm http://moon.ouhsc.edu/kfung/jty1/opaq/PathQuiz/A6I001-PQ01-M.htm]. Accessed on: 19 October 2010</ref> - [http://moon.ouhsc.edu/kfung/jty1/opaq/PathQuiz/PQ-Images/A6I001-3.gif histoplasma (ouhsc.edu)].
*** Have a "central dot"<ref>URL: [http://moon.ouhsc.edu/kfung/jty1/opaq/PathQuiz/A6I001-PQ01-M.htm http://moon.ouhsc.edu/kfung/jty1/opaq/PathQuiz/A6I001-PQ01-M.htm]. Accessed on: 19 October 2010</ref> - [http://moon.ouhsc.edu/kfung/jty1/opaq/PathQuiz/PQ-Images/A6I001-3.gif histoplasma (ouhsc.edu)].


==Coccidiomycosis==
==Coccidioidomycosis==
*''Coccidioides immitis'' - fungus, from soil, typical locations: lung, oral cavity.<ref name=Ref_WMSP3>{{Ref WMSP|3}}</ref>  
===General===
** Forms spherules 60-80 micrometres in size.<ref name=Ref_WMSP103>{{Ref WMSP|103}}</ref>  
*Organism: ''Coccidioides''.
** [http://commons.wikimedia.org/wiki/File:Mature_spherule_with_endospores_of_Coccidioides_immitis_PHIL_480_lores.jpg Coccidioides (commons.wikimedia.org)].
*Specific organism: ''Coccidioides immitis'' -  
**Usu. from soil.
*Typical locations: lung, oral cavity.<ref name=Ref_WMSP3>{{Ref WMSP|3}}</ref>  
 
===Microscopic===
Features:
* Forms spherules 60-80 micrometres in size.<ref name=Ref_WMSP103>{{Ref WMSP|103}}</ref>  


==Pneumocystis pneumonia (PCP) ==
Image:
*''Pneumocystis jirovecii'' (used to be called ''Pneumocystis carinii'') - fungus (that used to be considered a parasite), typical location: lung.
*[http://commons.wikimedia.org/wiki/File:Mature_spherule_with_endospores_of_Coccidioides_immitis_PHIL_480_lores.jpg Coccidioides (WC)].
**Clinical: Opportunistic infection. May have subtle finding on chest x-ray.
 
**"Dented ping-pong ball" appearance;<ref name=Ref_WMSP103>{{Ref WMSP|103}}</ref> - remember '''P'''C'''P''' = '''p'''ing-'''p'''ong.
==Pneumocystis pneumonia==
**Approximately 7-8 micrometres in size - [http://commons.wikimedia.org/wiki/File:Pneumocystosis_carinii_of_lung_in_AIDS_959_lores.jpg PCP (WP)].  [http://commons.wikimedia.org/w/index.php?title=Special%3ASearch&search=Pneumocystis+carinii&go=Go Several images are here (WC)].
Abbreviated ''PCP''.
===General===
*Organism: ''pneumocystis'',
*Specific organism: ''Pneumocystis jirovecii'' (used to be called ''Pneumocystis carinii'')  
**Fungus... used to be considered a parasite.
*Typical location: lung.
*Clinical: Opportunistic infection. May have subtle finding on chest x-ray.
 
===Microscopic===
Features:
*"Dented ping-pong ball" appearance;<ref name=Ref_WMSP103>{{Ref WMSP|103}}</ref> - remember '''P'''C'''P''' = '''p'''ing-'''p'''ong.
*Approximately 7-8 micrometres in size - [http://commons.wikimedia.org/wiki/File:Pneumocystosis_carinii_of_lung_in_AIDS_959_lores.jpg PCP (WP)].  [http://commons.wikimedia.org/w/index.php?title=Special%3ASearch&search=Pneumocystis+carinii&go=Go Several images are here (WC)].


==Cryptococcus==
==Cryptococcus==
*Usually ''C. neoformans'', fungus - opportunistic infection, typical location: lung.
===General===
*Most common fungus seen in CSF specimens.<ref name=Ref_APBR682>{{Ref APBR|682}}</ref>
*Specific organism: ''C. neoformans''.
*Opportunistic infection.
*Typical location: lung.
**Most common fungus seen in CSF specimens.<ref name=Ref_APBR682>{{Ref APBR|682}}</ref>


Appearance:
===Microscopic===
Features:
*Yeast:
*Yeast:
**Round/ovoid 5-15 micrometres (may resemble Histoplasma or Candida -- but often larger).
**Round/ovoid 5-15 micrometres (may resemble Histoplasma or Candida -- but often larger).
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==Cryptosporidiosis==
==Cryptosporidiosis==
===General===
===General===
*Caused by cryptosporidium.
*Caused by ''cryptosporidium''.
*Fecal-oral transmission.  
*Fecal-oral transmission.  
*Usu. in immunoincompetent individuals, e.g. [[HIV|HIV/AIDS]].
*Usu. in immunoincompetent individuals, e.g. [[HIV|HIV/AIDS]].
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==Candidiasis==
==Candidiasis==
*Commonly ''Candida albicans'' - yeast (fungus), locations: oral cavity, vagina.
===General===
*Commonly ''Candida albicans''.
*Yeast forms.
*Locations: oral cavity, vagina.
 
===Microscopic===
Features:
*''Dimorphic'' - seen in two forms:
*''Dimorphic'' - seen in two forms:
**Pseudohyphae<ref name=Ref_WMSP3>{{Ref WMSP|3}}</ref>  - collections of many ''C. albicans'' cells in a branching pattern.
**Pseudohyphae<ref name=Ref_WMSP3>{{Ref WMSP|3}}</ref>  - collections of many ''C. albicans'' cells in a branching pattern.
**Yeast form - single cells, 10 to 12 micrometres in diameter, gram positive.<ref>[http://pathmicro.med.sc.edu/mycology/mycology-3.htm http://pathmicro.med.sc.edu/mycology/mycology-3.htm]</ref>  
**Yeast form - single cells, 10 to 12 micrometres in diameter, gram positive.<ref>[http://pathmicro.med.sc.edu/mycology/mycology-3.htm http://pathmicro.med.sc.edu/mycology/mycology-3.htm]</ref>  
*Stains: PAS, methenamine silver.
 
*Images:
*Images:
**[http://pathmicro.med.sc.edu/mycology/candi4.jpg Candida (pseudohyphae) - methenamine silver (med.sc.edu)].
**[http://pathmicro.med.sc.edu/mycology/candi4.jpg Candida (pseudohyphae) - methenamine silver (med.sc.edu)].
**[http://commons.wikimedia.org/wiki/File:Candida_pap_1.jpg Candida on Pap test (WC)].
**[http://commons.wikimedia.org/wiki/File:Candida_pap_1.jpg Candida on Pap test (WC)].
===Stains===
Features:
*PAS +ve.
*Methenamine silver +ve.


==Blastomycosis==
==Blastomycosis==
===General===
*Usually ''Blastomyces dermatitidis'' - fungus.
*Usually ''Blastomyces dermatitidis'' - fungus.
*May be in the oral cavity.<ref name=Ref_WMSP3>{{Ref WMSP|3}}</ref>  
*May be in the oral cavity.<ref name=Ref_WMSP3>{{Ref WMSP|3}}</ref>  
*Histology = '''B'''road-based budding yeast -- is '''B'''lastomyces.<ref name=pmid12375640>PMID 12375640</ref>
 
===Microscopic===
Features:
*'''B'''road-based budding yeast -- is '''B'''lastomyces.<ref name=pmid12375640>PMID 12375640</ref>
**The interface between two separating fungi, i.e. fungi in the process of reproducing, is very large.
**The interface between two separating fungi, i.e. fungi in the process of reproducing, is very large.
*Images:
 
**[http://commons.wikimedia.org/wiki/File:Blastomycosis_cropped.JPG Blastomycosis (wikimedia.org)].
Images:
**[http://www.pathguy.com/lectures/blastomycosis.jpg Blastomycosis - budding (pathguy.com)].
*[http://commons.wikimedia.org/wiki/File:Blastomycosis_cropped.JPG Blastomycosis (wikimedia.org)].
**[http://www.lahey.org/Medical/InfectiousDiseases/ID_Blastomycosis.asp Blastomycosis - with broad budding (lahey.org)].
*[http://www.pathguy.com/lectures/blastomycosis.jpg Blastomycosis - budding (pathguy.com)].
*[http://www.lahey.org/Medical/InfectiousDiseases/ID_Blastomycosis.asp Blastomycosis - with broad budding (lahey.org)].


==Mucormycosis==
==Mucormycosis==
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*Causative organism: Mucorales.
*Causative organism: Mucorales.
**Kingdom: Fungi.
**Kingdom: Fungi.
**AKA ''Zygomycota'' (zygomycosis).
**[[AKA]] ''Zygomycota'' (zygomycosis).
*Assoc. with diabetes, immunodeficiency.
*Assoc. with [[diabetes]], immunodeficiency.


===Microscopic===
===Microscopic===

Revision as of 04:23, 15 November 2011

Fungi are microorganisms that are occasionally seen by pathologists.

Overview

  • There are lots of 'em. Below are a few of 'em.

Terminology:[1]

  • Hyphae = microscopic filamentous growth (of fungi) -- single cell.
  • Mycelial = filamentous network of hyphae.
  • Septae/septation = hyphae may be subdivided by septae -- if they aren't they are one mass of protoplasm. (?)
  • Dimorphism = exist in two forms; e.g. single cell (yeast) and mycelial growth.
  • Pseudohyphae = looks like hyphae --but branching pattern is created by separate cells.[2]

Tissue invasive fungi

Typically:[3]

Summary table

Name (disease) Kingdom Size Shape Stains Other (microscopic) Clinical References Image
Aspergillus (aspergillosis) Fungi ? Hyphae that branching
with 45 degrees angle 		PAS-D Fruiting heads when aerobic ? Immunosuppression [4] Aspergillus (WC), Aspergillus cytology (WC)
Zygomycota (zygomycosis);
more specific
Mucorales (mucormycosis) 		Fungi ? Branching hyphae with variable width ? Granulomata assoc. Diabetes, immunodeficient [4] Mucormycosis (homestead.com), Zygomycosis (WC)
Coccidioides, usually C. immitis
(coccidioidomycosis) 		Fungi Large - 20-60 micrometers,
endospores 1-5 micrometers 		Spherules Stains? Other? Immunodeficient [4] Coccidioidomycosis (med.sc.edu) C. immitis (WC) (webpathology.com)
Histoplasma (histoplasmosis) Fungi 2-5 micrometers Spherical GMS Intracellular (unlike candida), granulomata Source: soil with bird droppings [4] Histoplasmosis (WC)
Blastomyces (Blastomycosis) Fungi 5-15 micrometres Spherical (yeast) Stains? Granulomas, broad-based budding yeast Habitat: Northeast America, Africa [4][5] Blastomyces
Paracoccidioides (Paracoccidioidomycosis) Fungi 6-60 micrometres Spherical (yeast) Stains? Multiple budding "steering wheel" appearance Clinical??? [4] P. brasiliensis (WC).
Pneumocystis jirovecii (Pneumocystis carinii pneumonia; abbrev. PCP) Fungi (previously thought to be a protozoan) 7-8 micrometres "Dented ping-pong ball" GMS Usually in clusters of alveolar casts with a honeycomb appearance HIV/AIDS associated [6] PCP (WC)
Cryptococcosis Fungi 5-15 micrometres Yeast GMS Prominent (i.e. thick polysaccharide) capsule HIV/AIDS associated, most common CNS fungus [4] Crytococcosis - methenamine silver (WC), Crytococcosis - mucicarmine (WC).

Notes:

  • Bold text = key features.

Specific fungi

Histoplasmosis

General

  • Organism: Histoplasma.
  • Specific organism: Histoplasma capulatum.
  • Typical location: lung.

Microscopic

Features:

Coccidioidomycosis

General

  • Organism: Coccidioides.
  • Specific organism: Coccidioides immitis -
    • Usu. from soil.
  • Typical locations: lung, oral cavity.[9]

Microscopic

Features:

  • Forms spherules 60-80 micrometres in size.[7]

Image:

Pneumocystis pneumonia

Abbreviated PCP.

General

  • Organism: pneumocystis,
  • Specific organism: Pneumocystis jirovecii (used to be called Pneumocystis carinii)
    • Fungus... used to be considered a parasite.
  • Typical location: lung.
  • Clinical: Opportunistic infection. May have subtle finding on chest x-ray.

Microscopic

Features:

Cryptococcus

General

  • Specific organism: C. neoformans.
  • Opportunistic infection.
  • Typical location: lung.
    • Most common fungus seen in CSF specimens.[4]

Microscopic

Features:

  • Yeast:
    • Round/ovoid 5-15 micrometres (may resemble Histoplasma or Candida -- but often larger).
    • Thick mucopolysacchardie capsule + refractile centre.[4]
    • "Tear drop-shapped" budding pattern (useful to differentiate from Blastomyces, Histoplasma).[4]

Images:

Notes:

  • May be confused with corpora amylacea in the CNS, esp. as they (like cryptococci) stain for methenamine silver, Alcian blue, and PAS.[10]

Cryptosporidiosis

General

  • Caused by cryptosporidium.
  • Fecal-oral transmission.
  • Usu. in immunoincompetent individuals, e.g. HIV/AIDS.

Microscopic

Features:

  • Uniform spherical nodules 2-4 micrometres in diameter, typical location - GI tract brush border.
    • Bluish staining of brush border key feature - low power.

Images:

Notes:

  • Cryptosporidium parvum?[11]

Candidiasis

General

  • Commonly Candida albicans.
  • Yeast forms.
  • Locations: oral cavity, vagina.

Microscopic

Features:

  • Dimorphic - seen in two forms:
    • Pseudohyphae[9] - collections of many C. albicans cells in a branching pattern.
    • Yeast form - single cells, 10 to 12 micrometres in diameter, gram positive.[12]

Stains

Features:

  • PAS +ve.
  • Methenamine silver +ve.

Blastomycosis

General

  • Usually Blastomyces dermatitidis - fungus.
  • May be in the oral cavity.[9]

Microscopic

Features:

  • Broad-based budding yeast -- is Blastomyces.[13]
    • The interface between two separating fungi, i.e. fungi in the process of reproducing, is very large.

Images:

Mucormycosis

General

  • Causative organism: Mucorales.
    • Kingdom: Fungi.
    • AKA Zygomycota (zygomycosis).
  • Assoc. with diabetes, immunodeficiency.

Microscopic

Features:[4]

  • Branching hyphae variable width.
  • Granulomata associated.

Image:

See also

References

  1. ↑ http://www.fungionline.org.uk/1intro/3growth_forms.html
  2. ↑ http://pathmicro.med.sc.edu/mycology/mycology-3.htm
  3. ↑ CM 17 Apr 2009.
  4. ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 Lefkowitch, Jay H. (2006). Anatomic Pathology Board Review (1st ed.). Saunders. pp. 682. ISBN 978-1416025887.
  5. ↑ http://pathmicro.med.sc.edu/mycology/mycology-6.htm
  6. ↑ Lefkowitch, Jay H. (2006). Anatomic Pathology Board Review (1st ed.). Saunders. pp. 684. ISBN 978-1416025887.
  7. ↑ 7.0 7.1 7.2 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 103. ISBN 978-0781765275.
  8. ↑ URL: http://moon.ouhsc.edu/kfung/jty1/opaq/PathQuiz/A6I001-PQ01-M.htm. Accessed on: 19 October 2010
  9. ↑ 9.0 9.1 9.2 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 3. ISBN 978-0781765275.
  10. ↑ URL: http://flylib.com/books/en/2.953.1.17/1/. Accessed on: 15 December 2010.
  11. ↑ http://www.dpd.cdc.gov/dpdx/HTML/Cryptosporidiosis.htm
  12. ↑ http://pathmicro.med.sc.edu/mycology/mycology-3.htm
  13. ↑ PMID 12375640
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