Bladder
Miscellaneous
Staging

Author: Debra Zynger, M.D. (see Authors page)

Revised: 14 May 2018, last major update May 2018

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Staging[TI] bladder[TI] free full text[sb]
Cite this page: Zynger, D. Staging. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/bladderstaging.html. Accessed July 20th, 2018.

Pathologic TNM staging of bladder, AJCC 8th edition
Definition / general
  • Clinical staging is based on bimanual examination under anesthesia, imaging, biochemical and isotopic tests for metastases
  • Pathologic staging is based on review of TURBT (transurethral resection of bladder tumor), partial cystectomy or radical cystectomy specimens
  • Pathological stage is the most important determinant of treatment and prognosis for bladder cancer (Cancer 2000;88:2326)
  • Lamina propria invasion may be difficult to determine due to fragmentation, cautery, tangential sectioning and poorly oriented specimens
  • Muscularis propria invasion can be difficult to determine if there are insufficient muscle bundles to distinguish between hypertrophic muscularis mucosae and true muscularis propria
  • Accurate pathological stage can be assigned to TURBO (transurethral resection in one piece) specimens in most bladder cancer patients (Int J Urol 2010;17:708)
Primary tumor (pT)
  • pTX: Cannot be assessed
  • pT0: No evidence of primary tumor
  • pTa: Noninvasive papillary carcinoma
  • pTis: Carcinoma in situ
  • pT1: Invades lamina propria
  • pT2a: Invades inner half of muscularis propria
  • pT2b: Invades outer half of muscularis propria
  • pT3a: Microscopically invades perivesical tissue
  • pT3b: Macroscopically invades perivesical tissue
  • pT4a: Directly invades prostatic stroma, seminal vesicles, uterus or vagina
  • pT4b: Directly invades pelvic wall or abdominal wall
  • References: Amin: AJCC Cancer Staging Handbook, 8th Edition, 2018, NIH: Bladder Cancer Treatment [Accessed 14 May 2018]

    General staging notes:
  • Clinical management with respect to intravesicular BCG / chemotherapy and frequency of surveillance differs for high grade versus low grade tumors
  • Hyperplastic muscular mucosa may resemble muscularis propria (Am J Surg Pathol 2007;31:1420)
  • Adipose tissue often is present within deep lamina propria, usually as small localized aggregates and is always found within muscularis propria (superficial and deep); beware of inappropriate staging as pT3 due to tumor infiltration of adipose tissue, particularly in TURBT specimens (Am J Surg Pathol 2000;24:1286)

    Lamina propria (pT1):
  • Lamina propria contains connective tissues between urothelium and detrusor muscle (muscularis propria), made of loose stroma, variably sized blood vessels and thin muscle bands of muscularis mucosae
  • pTa cases may actually be invasive when studied by electron microscopy, significance unclear (Am J Clin Pathol 2003;120:188); invasion of lamina propria can be subjective and is not as clinically crucial as invasion of muscularis propria (pT2)
  • Has nests, clusters or single tumor cells, sometimes with prominent retraction artifact (does not represent lymphovascular invasion)
  • Often has desmoplastic or inflammatory stromal response and absent or irregular basement membrane, not seen with low grade papillary carcinomas with inverted pattern
  • Tumor cells often have abundant eosinophilic cytoplasm at advancing edge ("paradoxical differentiation")
  • If tumor cells hug the mucosa, they should be more anaplastic than mucosa cells
  • Pitfalls in diagnosis include tangential sectioning, poor specimen orientation, inflammation, thermal injury, deceptively bland cytology and pseudoinvasive nests of benign proliferative urothelial cells (Pathology 2003;35:484)
  • Substaging of pT1 based on muscularis mucosa is technically difficult and not reproducible (Mod Pathol 1996;9:1035)
  • 50% recur

    Muscularis propria (pT2):
  • Muscularis propria is thick aggregated muscle bundles of detrusor muscle; must distinguish from muscularis mucosa
  • Assessment of muscularis propria invasion is very important (pTa / pT1 vs. pT2)
  • Mention whether muscularis propria is present in biopsies and if invasion is present
  • Don’t confuse occasionally prominent fascicles of muscularis mucosa that is part of lamina propria (more common in women) with muscularis propria invasion (hypertrophic muscularis mucosa)
  • Cannot substage pT2 as pT2a or pT2b unless have full thickness and well oriented biopsy of bladder
  • Muscularis propria invasion implies tumor infiltrating thick smooth muscle bundles
  • Can use trichrome or HHF to highlight all smooth muscle tissue to determine if muscularis mucosa or muscularis propria is invaded
  • Smoothelin antibody may be useful to distinguish muscularis propria from muscularis mucosa (but see Virchows Arch 2011;458:665)
  • Tumor cells should "carve out" the muscle bundles, often desmoplastic response should be present
  • Can assess presence but not depth of muscularis propria invasion in TURBT specimen

    Perivesical fat (pT3):
  • Perivesical adipose tissue is deep to muscularis propria, but is also present within deep lamina propria, usually as small localized aggregates and within muscularis propria (superficial and deep)
  • Beware of inappropriate staging as pT3 due to tumor infiltration of adipose tissue, particularly in TURBT specimens (Am J Surg Pathol 2000;24:1286)
  • For node positive radical cystectomy patients with meticulous lymph node dissection and thorough histologic examination, extracapsular extension has prognostic value but N1 vs. N2 does not (Am J Surg Pathol 2005;29:89)
  • Metastases to lymph nodes in 25% of invasive tumors; also to lung, liver, bone and CNS
  • Often dysplasia or carcinoma in situ elsewhere in bladder; also in ureters, bladder neck, urethra, prostatic ducts and seminal vesicle
  • 10 year survival only 40% for high grade tumors
Regional lymph nodes (pN)
  • pNX: Cannot be assessed
  • pN0: No regional lymph node metastasis
  • pN1: Metastasis in 1 true pelvic lymph node
  • pN2: Metastasis in greater than 1 true pelvic lymph node
  • pN3: Metastasis in common iliac lymph node
    (regional lymph nodes = true pelvic lymph node includes perivesical, hypogastric / deep obturator / fossa of Marcille / internal iliac, obturator, external iliac and presacral / sacral / lateral sacral / sacral promontory)

    Notes
  • For node positive radical cystectomy patients with meticulous lymph node dissection and thorough histologic examination, extracapsular extension has prognostic value but N1 vs. N2 based on size (AJCC 6th edition classification) does not (Am J Surg Pathol 2005;29:89)
Distant metastasis (pM)
  • pM1a: Metastasis in nonregional lymph node (ex: caval / aortic, inguinal)
  • pM1b: Metastasis in other distant site
AJCC prognostic stage groups
Stage group 0a: Ta N0 M0
Stage group 0is: Tis N0 M0
Stage group I: T1 N0 M0
Stage group II: T2a - 2b N0 M0
Stage group IIIA: T3a - 4a N0 M0
T1 - 4a N1 M0
Stage group IIIB: T1 - 4a N2 - 3 M0
Stage group IVA: T4b any N M0
any T any N M1a
Stage group IVB: any T any N M1b
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by Debra Zynger, M.D.

Noninvasive low grade (pTa)

Microinvasion (pT1)

Lamina propria invasion (pT1)

Within muscularis mucosae (pT1)


Within muscularis propria (pT2)

Within perivesicular adipose (pT3)

Lung metastasis (pM1)



Images hosted on other servers:
Missing Image

Diagrams of cancer staging

Virtual slides

Images hosted on other servers:

pT1 bladder cancer

Additional references