Bladder & urothelial tract

Urothelial neoplasms - noninvasive

Carcinoma in situ

Last author update: 1 December 2014
Last staff update: 27 February 2024 (update in progress)

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PubMed Search: Bladder carcinoma in situ

Monika Roychowdhury, M.D.
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Cite this page: Roychowdhury M. Carcinoma in situ. website. Accessed April 15th, 2024.
Definition / general
  • Flat lesion composed of cells in mid to upper epithelium with high cytologic grade
  • By definition, no invasion into lamina propria
  • Note: high grade non-invasive papillary lesions are NOT designated carcinoma in situ to avoid confusion
  • Also known as high grade intraurothelial neoplasia (HG IUN), severe dysplasia (sometimes)
  • De novo CIS constitutes less than 3% of all urothelial neoplasms, but occurs in 45% with concurrent invasive bladder carcinoma
Clinical features
  • Symptoms are similar to cystitis; hematuria is common
  • 20 - 80% of CIS patients develop invasive disease if left untreated
  • Confers poorer prognosis in patients with coexisting noninvasive papillary urothelial carcinoma
  • Often involves urothelium in other areas of GU tract
  • Associated with multifocal high grade invasive carcinoma
  • Presence should be included in pathology reports
Prognostic factors
Case reports
Gross description
  • Flat, grossly erythematous, granular or cobblestone mucosa
  • No mass
  • May involve large areas of mucosal surface, ureters, urethra
Microscopic (histologic) description
  • Flat lesion composed of cells with large, irregular, hyperchromatic nuclei, prominent nuclear pleomorphism, high N/C ratio, mitotic figures in mid to upper epithelium
  • Atypia may not be full thickness
  • Epithelium is often denuded
  • Nuclear size is 5x that of lymphocytes versus 2x lymphocytes for normal urothelium (Hum Pathol 2001;32:997)
  • Also (but less important) loss of polarity, nuclear crowding, irregular thickness of urothelium
  • Cells are not cohesive, leading to shedding into urine
  • Occasionally present in prostatic ducts, spreads by intramucosal extension
  • Note: high grade non-invasive papillary lesions are NOT designated as carcinoma in situ to avoid confusion
  • Large cells with pleomorphism, large cells without pleomorphism, small cell, clinging (single layer of atypical cells on denuded urothelium), cancerization of urothelium (pagetoid - Hum Pathol 1993;24:1199, undermining or overriding)
  • Pattern need not be included in surgical pathology report
  • Microinvasion (2 mm or less) demonstrates invasive cells with retraction artifact mimicking vascular invasion (77% of cases of microinvasion)
  • Also nests or irregular cords, rarely invades as isolated single cells with or without desmoplasia (Am J Surg Pathol 2001;25:356)
Microscopic (histologic) images

Contributed by Sean R. Williamson, M.D. and Bhavesh Papadi, M.D. (Case #331)
Caption Caption Caption

Ureter CIS


Denuded urothelium

Various images

Additional images

Contributed by @AnaPath10 on Twitter
Bladder carcinoma in situ Bladder carcinoma in situ Bladder carcinoma in situ

Bladder carcinoma in situ

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Loss of polarization

Broadened urothelium

Narrowed urothelium

Pagetoid pattern

Cytology description
  • Cytology is 95% sensitive for carcinoma in situ
  • Nuclear changes of carcinoma with minimal pleomorphism
  • Numerous high-grade neoplastic cells
  • Relatively clean background
  • Image analysis of bladder wash cytology may be comparable to "expert" cytologic review (Mod Pathol 1997;10:976)

Histopathology Bladder Transitional Carcinoma in situ

Positive stains
Molecular / cytogenetics description
  • Monoclonal with aneuploid DNA and more abnormal microsatellites than corresponding invasive carcinoma, if present (Hum Pathol 2009;40:988)
  • Has somatic mismatch repair protein down-regulation and accumulation of tumor suppressor gene microsatellite abnormalities
  • Molecular pattern of CIS is divergent from coexistent muscle invasive urothelial carcinoma
  • Deletion of 9p21 or polysomy of #9 (Hum Pathol 2008;39:527)
Differential diagnosis
  • Denuding cystitis: cells may look malignant
  • Denuded urothelium:
    • Extensively denuded epithelium is often seen in CIS ("clinging CIS" or "denuding cystitis")
    • However residual malignant cells required for diagnosis
    • Deeper sectioning of tissue block or examination of von Brunn nests may be helpful if epithelium is denuded
  • Dysplasia: less severe atypia although distinction may be difficult
  • Post-topical therapy for high grade urothelial carcinoma: still has capillaries
  • Radiation effect: cells still cohesive, may have distinctive nuclear borders, may resemble pagetoid variant of CIS
  • Reactive atypia: less pleomorphic nuclei than CIS; patchy CK20 in umbrella cells only, p53 weak/negative, CD44 diffusely or focally positive vs. CIS which is intensely CK20+ (81%), p53+ (57%), CD44- (100%, Am J Surg Pathol 2001;25:1074)
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