Difference between revisions of "Muscularis propria invasion in the urinary bladder"
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Staging of bladder cancer is dealt with in the ''[[bladder cancer staging]]'' article. | Staging of bladder cancer is dealt with in the ''[[bladder cancer staging]]'' article. | ||
'''''Muscle invasive bladder cancer''''' redirects to this article and refers to invasion of the ''muscularis propria''. | '''''Muscle invasive bladder cancer''''' redirects to this article and refers to invasion of the ''muscularis propria''. | ||
''Bladder muscularis propria invasion'' and ''urinary bladder muscularis propria invasion'' redirect to this article. | |||
==General== | ==General== |
Revision as of 18:27, 23 January 2017
The presence or absence of muscularis propria invasion in the urinary bladder is a very important determination, as the clinical management changes between T1 and T2:
- T1: usually conservative treatment (local excision).
- T2: radical treatment (cystectomy or cystoprostatectomy).
A thin layer of discontinous muscularis mucuosae (MM) is present and, especially if hypertrophic, may be confused with muscuaris propria (MP).
Staging of bladder cancer is dealt with in the bladder cancer staging article.
Muscle invasive bladder cancer redirects to this article and refers to invasion of the muscularis propria.
Bladder muscularis propria invasion and urinary bladder muscularis propria invasion redirect to this article.
General
Comparing muscularis propria and muscularis mucosae
A comparison between muscularis propria and muscularis mucosae - adapted from Paner et al.:[1]
Feature | Muscularis mucosae | Muscularis propria |
---|---|---|
Outline/border | typically irregular (frayed edges) | usually regular (circumscribed) |
Size of bundles ‡ | classically "small", often "large" (hypertrophic) | usually "large" |
Isolated fibres | yes | no |
Location in bladder | less common in trigone, dome very common | everywhere |
Depth † | superficial, occ. deep | deep |
Notes:
- † The lamina propria thickness varies with location. It is thinnest in the trigone (0.5-1.6 mm) and thickest in the dome (1.0-3.1 mm).
- ‡ Small is defined as <4 muscle fibres; large >= 4 muscle fibres.
- The presence of hyperplastic bundles ranges from ~20% in the trigone to ~70% in the dome.
Images
Microscopic
Rational assessment of muscularis propria invasion
To call muscularis propria invasion:
- Definite tumour must be between muscle.
- Muscle bundles must be thick.
- Multiple bundles must be adjacent to one another.
- Should not be superficial - surface epithelium if present should be distant.
DDx:
- Invasion of hypertrophic muscularis mucosae.
Images
Sign out
Cannot exclude MP invasion
Urinary Bladder Tumour, Transurethral Resection: - INVASIVE HIGH-GRADE UROTHELIAL CARCINOMA. -- Extensive invasion into at least the lamina propria. - Negative for definite muscularis propria, see comment. Comment: The tumour is seen around bundles of smooth muscle that are favoured to represent muscularis mucosa; however, obliterated muscularis propria cannot be excluded. Correlation with the clinical findings is required. Additional transurethral sampling and/or imaging to assess the muscularis propria is suggested.
See also
References
- ↑ Paner, GP.; Ro, JY.; Wojcik, EM.; Venkataraman, G.; Datta, MW.; Amin, MB. (Sep 2007). "Further characterization of the muscle layers and lamina propria of the urinary bladder by systematic histologic mapping: implications for pathologic staging of invasive urothelial carcinoma.". Am J Surg Pathol 31 (9): 1420-9. doi:10.1097/PAS.0b013e3180588283. PMID 17721199.