plasmacytoid urothelial carcinoma
The WHO classification of 2004 defines new histological and molecular variants of urothelial carcinoma. However there are limited data available on the clinico-pathological characteristics or prognosis of these variants.
In summary, PUC is a aggressive variant of bladder cancer with molecular features of advanced bladder cancer and evidence of WNT pathway activation in some of the cases.
Synopsuis
high-grade tumor
molecular features of aggressive urothelial carcinoma
usually diagnosed in advanced pathological stage (64% pT3, 23% pT4)
metastases in 60 % of the patients
Prognosis
Average survival of PUC treated with radical cystectomy and adjuvant chemotherapy is lower than what is typically seen for comparable conventional urothelial carcinomas.
Immunochemistry (#20878954#)
87% of the PUCs show a negative or strongly reduced membranous staining of E-cadherin. (#20878954#, #20818341#)
Beta-catenin staining is negative in 22.5 % and 16.7% of the remaining tumors show nuclear accumulation.
Aberrant CK20 expression (negative or >10% of cells stained) and negative CK7 staining is found in 100% and 22.6 %, respectively.
97% reveal positive staining for PAN-CK.
CD138 is positive in 78 %
MUM-1 expression is negative in all cases.
Cytogenetics (#20878954#)
Multi-target fluorescence in situ hybridization showed all PUCs to be highly aneuploid and polysomic.
Deletions on chromosome 9p21 seem to play an important role in this variant.
Molecular biology (#20878954#)
FGFR3 and PIK3CA mutation analyses yield no mutations in any of the PUCs analyzed.
TP53 mutation analysis show mutations in 29%.
References
The plasmacytoid carcinoma of the bladder - rare variant of aggressive urothelial carcinoma. Keck B, Stoehr R, Wach S, Rogler A, Hofstaedter F, Lehmann J, Montironi R, Sibonye M, Fritsche HM, Lopez-Beltran A, Epstein JI, Wullich B, Hartmann A. Int J Cancer. 2010 Sep 28. PMID: #20878954#
E-cadherin expression in plasmacytoid, signet ring cell and micropapillary variants of urothelial carcinoma: comparison with usual-type high-grade urothelial carcinoma. Lim MG, Adsay NV, Grignon DJ, Osunkoya AO. Mod Pathol. 2010 Sep 3. PMID: #20818341#