Bladder
Urothelial carcinoma-invasive
With squamous differentiation



Topic Completed: 01 December 2014

Revised: 24 December 2018

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

PubMed Search: Urothelial carcinoma invasion with squamous differentiation
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Cite this page: Pernick N With squamous differentiation. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/bladdersquamousdiff.html. Accessed January 22nd, 2019.
Definition / general
  • Mixed variant with malignant urothelial and squamous components (either component may be in situ only)
Epidemiology
Clinical features
Microscopic (histologic) description
  • Associated with high grade urothelial carcinoma
  • By definition, must also have an identifiable malignant urothelial component (may be only carcinoma in situ)
  • Squamous component has nests of malignant squamous epithelium, characterized by polygonal cells and evidence of keratinization (dyskeratosis, keratin pearls) or intercellular bridges
  • Squamous component may have basaloid or clear cell features
  • Associated with eosinophils (J Clin Pathol 1984;37:500)
  • Recommended to report percentage of squamous component
Microscopic (histologic) images

High grade tumor



Images hosted on other servers:
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Keratin pearl formation

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Urothelial carcinoma with squamous differentiation

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Fig 1: Trigone mucosa

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Poorly differentiated tumor
with squamous differentiation

Positive stains
Negative stains
  • Squamous component: uroplakins (positive in urothelial component), CK20
Differential diagnosis