Which immunostain pattern is typically observed in urothelial carcinoma immunophenotype?

• A. CK7+, GATA3+, HMWCK+
• B. Vimentin+, CK20-
• C. Vimentin-, HMWCK-
• D. CK7-, GATA3-

Answer: (A)

Immunophenotyping uses marker patterns to identify tissue origin and support a urothelial lineage. Urothelial carcinoma is typically positive for CK7 and GATA3, reflecting urothelial differentiation, and it also commonly shows positivity for high molecular weight cytokeratins (HMWCK). This combination—CK7 positive, GATA3 positive, and HMWCK positive—best captures the characteristic immunophenotype of urothelial carcinoma, helping distinguish it from tumors of other origins.

CK7 is a cytokeratin commonly expressed in urothelium, GATA3 is a sensitive marker for urothelial carcinoma, and HMWCK (34βE12) highlights basal-type cytokeratins present in urothelial cells. When these markers align as positive together, they strongly point to urothelial lineage.

Other patterns are less typical. Vimentin positivity is not a defining feature of urothelial carcinoma and can appear in more mesenchymal or sarcomatoid contexts. CK20 expression can be variable in urothelial cancers, and a pattern lacking CK7 or GATA3 would make urothelial origin less likely. An HMWCK-negative or CK7-negative profile would also be atypical for urothelial carcinoma.

In short, the CK7+, GATA3+, HMWCK+ pattern most clearly aligns with the expected immunophenotype of urothelial carcinoma.