Difference between revisions of "Mucinous tumours of the appendix"

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#redirect [[Vermiform_appendix#Mucinous_tumours_of_the_appendix]]
{{ Infobox external links
| Name          = Mucinous tumours of the appendix
| EHVSC          = 10183
| pathprotocols  =
| wikipedia      =
| pathoutlines  =
}}
'''Mucinous tumours of the appendix''' are uncommon tumours of the [[vermiform appendix]] that can have a benign or [[malignant]] behaviour.
 
'''Benign appendiceal [[mucocele]]''' and '''appendiceal mucocele''' redirect here.
==General==
*There are many classifications and they are controversial.<ref name=pmid21970481>{{Cite journal  | last1 = Panarelli | first1 = NC. | last2 = Yantiss | first2 = RK. | title = Mucinous neoplasms of the appendix and peritoneum. | journal = Arch Pathol Lab Med | volume = 135 | issue = 10 | pages = 1261-8 | month = Oct | year = 2011 | doi = 10.5858/arpa.2011-0034-RA | PMID = 21970481 }}</ref>
**The controversy centres on whether to call all mucinous tumours outside of the appendix ''adenocarcinoma'' - regardless of whether they have atypia & show invasion.
*''Panarelli and Yantiss'' created a nice summary table - that compare the classifications - see: [http://www.archivesofpathology.org/action/showFullPopup?id=i1543-2165-135-10-1261-t01&doi=10.5858%2Farpa.2011-0034-RA comparison of classifications (archivesofpathology.org)].<ref name=pmid21970481/>
*In women - an ovarian primary must be excluded.
**Concurrent ''bilateral'' ovarian tumours suggests the tumour originated from the appendix and spread to the ovaries.
*[[Onlinepathology]] prefers the classification of Misdraji,<ref name=pmid12883241>{{cite journal |author=Misdraji J, Yantiss RK, Graeme-Cook FM, Balis UJ, Young RH |title=Appendiceal mucinous neoplasms: a clinicopathologic analysis of 107 cases |journal=Am. J. Surg. Pathol. |volume=27 |issue=8 |pages=1089–103 |year=2003 |month=August |pmid=12883241 |doi= |url=http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=0147-5185&volume=27&issue=8&spage=1089}}</ref> as it is the least complicated
 
===Misdraji classification===
*Benign - ''low grade mucinous tumour''.
*Borderline - ''mucinous tumour of uncertain malignant potential'' or ''borderline mucinous tumour''.
*Malignant - ''[[mucinous adenocarcinoma]]''.
 
Five year survival (in a series of 107 cases) as per Misdraji classification:<ref name=pmid12883241/>
{| class="wikitable sortable"
!Tumour
!Five year survival
|-
|LAMN
|100%
|-
|LAMN extra-appendiceal spread
|86%
|-
|MACA
|44%
|-
|}
*LAMN = low-grade appendiceal mucinous neoplasm.
*LAMN extra-appendiceal = low-grade appendiceal mucinous neoplasm with extra-appendiceal spread.
*MACA = mucinous adenocarcinoma of the appendix.
 
===World Health Organization classification===
WHO classification:
*Adenoma with low-grade dysplasia.
*Adenoma with high-grade dysplasia.
*Low-grade invasive mucinous adenocarcinoma
**Confined to the appendiceal wall.
**Outside of the appendix.
*High-grade invasive mucinous adenocarcinoma.
 
===Comparison between Misdraji and WHO classification===
Adapted from ''Panarelli and Yantiss'':<ref name=pmid21970481>{{Cite journal  | last1 = Panarelli | first1 = NC. | last2 = Yantiss | first2 = RK. | title = Mucinous neoplasms of the appendix and peritoneum. | journal = Arch Pathol Lab Med | volume = 135 | issue = 10 | pages = 1261-8 | month = Oct | year = 2011 | doi = 10.5858/arpa.2011-0034-RA | PMID = 21970481 }}</ref>
{| class="wikitable sortable"
! Stage
! Cytologic dysplasia
! Misdraji
! World Health Organization
|-
| Confined to the mucosa
| low-grade
| low-grade appendiceal mucinous neoplasm (LAMN)
| mucinous adenoma, negative for high-grade dysplasia
|-
| Confined to the mucosa
| high-grade
| non-invasive mucinous cystadenocarcinoma of the appendix
| mucinous adenoma with high-grade dysplasia
|-
| At least into the submucosa, confined to the appendix
| low-grade
| low-grade appendiceal mucinous neoplasm (LAMN)
| invasive mucinous adenocarcinoma, low-grade
|-
| At least into the submucosa, confined to the appendix
| high-grade
| mucinous adenocarcinoma of the appendix (MACA)
| invasive mucinous adenocarcinoma, high-grade
|-
| Extra-appendiceal spread
| low-grade
| low-grade appendiceal mucinous neoplasm (LAMN)
| invasive mucinous adenocarcinoma, low-grade
|-
| Extra-appendiceal spread
| high-grade
| mucinous adenocarcinoma of the appendix (MACA)
| invasive mucinous adenocarcinoma, high-grade
|}
 
==Microscopic==
===Low-grade appendiceal mucinous neoplasm===
*[[AKA]] ''benign mucinous tumour of the appendix''.
 
Microscopic:
*Single layer of epithelium with ''tufts''.
**Vaguely resemble ''serrations'', i.e. the ''saw-tooth'' pattern in hyperplastic polyps of the colon.
*Mucin contained (inside appendix only).
*No marked nuclear atypia.
 
Note:
*May be deceptively bland appearing from a cytologic perspective.
 
Images:
*[http://www.nature.com/modpathol/journal/v17/n12/fig_tab/3800212f1.html LAMN - low mag. (nature.com)].<ref name=pmid15354187/>
*[http://www.nature.com/modpathol/journal/v17/n12/fig_tab/3800212f3.html LAMN - high mag. (nature.com)].<ref name=pmid15354187>{{Cite journal  | last1 = Misdraji | first1 = J. | last2 = Burgart | first2 = LJ. | last3 = Lauwers | first3 = GY. | title = Defective mismatch repair in the pathogenesis of low-grade appendiceal mucinous neoplasms and adenocarcinomas. | journal = Mod Pathol | volume = 17 | issue = 12 | pages = 1447-54 | month = Dec | year = 2004 | doi = 10.1038/modpathol.3800212 | PMID = 15354187 }}</ref>
*[http://pathlabmed.typepad.com/surgical_pathology_and_la/2012/02/digital-case-simple-mucocele-of-the-appendix.html Appendiceal mucocele (pathlabmed.typepad.com)].
 
===Low-grade appendiceal mucinous neoplasm with extra-appendiceal spread===
*[[AKA]] ''mucinous borderline tumour of the appendix''.
 
Microscopic:
*Same as LAMN but mucin outside of the appendix.
*Cells in mucin, i.e. cellular mucin.
 
===Mucinous adenocarcinoma of the appendix===
*[[AKA]] ''malignant mucinous tumour of the appendix''.
 
Microscopic:
*Marked nuclear pleomorphism.
*Invasion into the appendiceal wall.
 
==Sign out==
===LAMN===
<pre>
VERMIFORM APPENDIX, APPENDECTOMY:
- LOW-GRADE APPENDICEAL MUCINOUS NEOPLASM.
- ACUTE APPENDICITIS.
- ACUTE PERIAPPENDICITIS.
</pre>
 
<pre>
VERMIFORM APPENDIX AND CECUM, APPENDECTOMY WITH CECAL CUFF:
- LOW-GRADE APPENDICEAL MUCINOUS NEOPLASM (MUCINOUS CYSTADENOMA).
- MARGINS NEGATIVE FOR MUCINOUS NEOPLASM.
 
COMMENT:
No extra-appendiceal mucin is identified. There is no invasion into the appendiceal wall.
</pre>
 
<pre>
APPENDIX, APPENDECTOMY:
- APPENDICEAL MUCINOUS CYSTADENOMA WITH EXTENSIVE CALCIFICATION.
-- NEGATIVE FOR HIGH-GRADE DYSPLASIA.
- NEGATIVE FOR MALIGNANCY.
</pre>
 
==See also==
*[[Vermiform appendix]].
*[[Mucinous carcinoma]].
 
==References==
{{Reflist|2}}
 
[[Category:Vermiform appendix]]

Revision as of 01:19, 4 April 2014

Mucinous tumours of the appendix
External resources
EHVSC 10183

Mucinous tumours of the appendix are uncommon tumours of the vermiform appendix that can have a benign or malignant behaviour.

Benign appendiceal mucocele and appendiceal mucocele redirect here.

General

  • There are many classifications and they are controversial.[1]
    • The controversy centres on whether to call all mucinous tumours outside of the appendix adenocarcinoma - regardless of whether they have atypia & show invasion.
  • Panarelli and Yantiss created a nice summary table - that compare the classifications - see: comparison of classifications (archivesofpathology.org).[1]
  • In women - an ovarian primary must be excluded.
    • Concurrent bilateral ovarian tumours suggests the tumour originated from the appendix and spread to the ovaries.
  • Onlinepathology prefers the classification of Misdraji,[2] as it is the least complicated

Misdraji classification

  • Benign - low grade mucinous tumour.
  • Borderline - mucinous tumour of uncertain malignant potential or borderline mucinous tumour.
  • Malignant - mucinous adenocarcinoma.

Five year survival (in a series of 107 cases) as per Misdraji classification:[2]

Tumour Five year survival
LAMN 100%
LAMN extra-appendiceal spread 86%
MACA 44%
  • LAMN = low-grade appendiceal mucinous neoplasm.
  • LAMN extra-appendiceal = low-grade appendiceal mucinous neoplasm with extra-appendiceal spread.
  • MACA = mucinous adenocarcinoma of the appendix.

World Health Organization classification

WHO classification:

  • Adenoma with low-grade dysplasia.
  • Adenoma with high-grade dysplasia.
  • Low-grade invasive mucinous adenocarcinoma
    • Confined to the appendiceal wall.
    • Outside of the appendix.
  • High-grade invasive mucinous adenocarcinoma.

Comparison between Misdraji and WHO classification

Adapted from Panarelli and Yantiss:[1]

Stage Cytologic dysplasia Misdraji World Health Organization
Confined to the mucosa low-grade low-grade appendiceal mucinous neoplasm (LAMN) mucinous adenoma, negative for high-grade dysplasia
Confined to the mucosa high-grade non-invasive mucinous cystadenocarcinoma of the appendix mucinous adenoma with high-grade dysplasia
At least into the submucosa, confined to the appendix low-grade low-grade appendiceal mucinous neoplasm (LAMN) invasive mucinous adenocarcinoma, low-grade
At least into the submucosa, confined to the appendix high-grade mucinous adenocarcinoma of the appendix (MACA) invasive mucinous adenocarcinoma, high-grade
Extra-appendiceal spread low-grade low-grade appendiceal mucinous neoplasm (LAMN) invasive mucinous adenocarcinoma, low-grade
Extra-appendiceal spread high-grade mucinous adenocarcinoma of the appendix (MACA) invasive mucinous adenocarcinoma, high-grade

Microscopic

Low-grade appendiceal mucinous neoplasm

  • AKA benign mucinous tumour of the appendix.

Microscopic:

  • Single layer of epithelium with tufts.
    • Vaguely resemble serrations, i.e. the saw-tooth pattern in hyperplastic polyps of the colon.
  • Mucin contained (inside appendix only).
  • No marked nuclear atypia.

Note:

  • May be deceptively bland appearing from a cytologic perspective.

Images:

Low-grade appendiceal mucinous neoplasm with extra-appendiceal spread

  • AKA mucinous borderline tumour of the appendix.

Microscopic:

  • Same as LAMN but mucin outside of the appendix.
  • Cells in mucin, i.e. cellular mucin.

Mucinous adenocarcinoma of the appendix

  • AKA malignant mucinous tumour of the appendix.

Microscopic:

  • Marked nuclear pleomorphism.
  • Invasion into the appendiceal wall.

Sign out

LAMN

VERMIFORM APPENDIX, APPENDECTOMY:
- LOW-GRADE APPENDICEAL MUCINOUS NEOPLASM.
- ACUTE APPENDICITIS.
- ACUTE PERIAPPENDICITIS. 

VERMIFORM APPENDIX AND CECUM, APPENDECTOMY WITH CECAL CUFF:
- LOW-GRADE APPENDICEAL MUCINOUS NEOPLASM (MUCINOUS CYSTADENOMA).
- MARGINS NEGATIVE FOR MUCINOUS NEOPLASM.

COMMENT:
No extra-appendiceal mucin is identified. There is no invasion into the appendiceal wall.

APPENDIX, APPENDECTOMY:
- APPENDICEAL MUCINOUS CYSTADENOMA WITH EXTENSIVE CALCIFICATION.
-- NEGATIVE FOR HIGH-GRADE DYSPLASIA.
- NEGATIVE FOR MALIGNANCY.

See also

References

  1. ↑ 1.0 1.1 1.2 Panarelli, NC.; Yantiss, RK. (Oct 2011). "Mucinous neoplasms of the appendix and peritoneum.". Arch Pathol Lab Med 135 (10): 1261-8. doi:10.5858/arpa.2011-0034-RA. PMID 21970481.
  2. ↑ 2.0 2.1 Misdraji J, Yantiss RK, Graeme-Cook FM, Balis UJ, Young RH (August 2003). "Appendiceal mucinous neoplasms: a clinicopathologic analysis of 107 cases". Am. J. Surg. Pathol. 27 (8): 1089–103. PMID 12883241. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=0147-5185&volume=27&issue=8&spage=1089.
  3. ↑ 3.0 3.1 Misdraji, J.; Burgart, LJ.; Lauwers, GY. (Dec 2004). "Defective mismatch repair in the pathogenesis of low-grade appendiceal mucinous neoplasms and adenocarcinomas.". Mod Pathol 17 (12): 1447-54. doi:10.1038/modpathol.3800212. PMID 15354187.
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