Urothelial carcinoma-invasive
With squamous differentiation

Author: Nat Pernick, M.D. (see Authors page)

Revised: 20 July 2016, last major update December 2014

Copyright: (c) 2003-2016,, Inc.

PubMed Search: Urothelial carcinoma invasion with squamous differentiation
Cite this page: With squamous differentiation. website. Accessed October 19th, 2018.
Definition / general
  • Mixed variant with malignant urothelial and squamous components (either component may be in situ only)
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

Images hosted on Pathout server:

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