Coexpression of cytokeratins 7 and 20 confirms urothelial carcinoma presenting as an intrarenal tumor

Keratin expression in human tissues and neoplasms

“…Since renal carcinomas may arise from proximal tubules, distal tubules, or collecting ducts, they may express different keratin profiles. The vast majority of cases of conventional renal carcinomas are negative for both K7 and K20 (Figure 5), whereas pelvic transitional cell carcinomas are positive for K7, K20, or both 82 , 91 , 173 . Unlike conventional renal carcinoma, papillary, collecting duct and chromophobe renal carcinomas are usually positive for K7 (Figure 5).…”

Cytokeratin 7: a useful adjunct in the diagnosis of chromophobe renal cell carcinoma

“…A growing body of literature has shown cytokeratin 7 to be of use in characterizing the nature of neoplasms in many organ systems, including the gastrointestinal tract, 7 lung 7 and the lower genitourinary tract 8 . Several published case series uniformly state that cytokeratin 7 is characteristically negative in renal cell carcinoma, 7 , 9 , 10 but in the main these studies do not state the subtype of renal cell carcinoma which has been investigated. However, there is evidence that certain subtypes of renal cell carcinoma do express cytokeratin 7.…”

P63 Immunoreactivity Distinguishes Upper Urinary Tract Transitional-cell Carcinoma and Renal-cell Carcinoma Even in Poorly Differentiated Tumors

“…However, a correct diagnosis is essential with respect to surgical treatment and follow-up because of the well known risk for tumor recurrence in the ureter and/or bladder in patients with pelvic TCC. In diagnostically problematic cases, keratin subtyping is usually applied because the majority of TCCs co-express keratin 7 and 20 in contrast to RCCs (Han and Duszak 1999;Chu and Weiss 2002). P63 comprises at least six different protein isoforms with homology to the tumor suppressor protein p53, which are generated from a single gene by two promoters and alternative splicing of the primary RNA transcript.…”