Uroplakin as a marker for typing metastatic transitional cell carcinoma on fine-needle aspiration specimens.
BACKGROUND
Immunohistological markers specific for a single type of epithelium are rare. Recently, urothelium tissue-specific genes were cloned. The genes encoded a family of transmembrane proteins, uroplakins, that are expressed only in urothelial mucosa. Using uroplakin antibodies on paraffin-embedded tissue, a previous study demonstrated positive staining in 66% of metastatic transitional cell carcinoma (TCC) cases and negative staining in all other tumors (including breast, ovarian, lung, and gastrointestinal carcinomas) tested. The current study addresses the diagnostic value of uroplakins in conventional fine-needle aspiration (FNA) material in establishing a diagnosis of metastatic TCC.


METHODS
Representative slides from 27 FNA cases of metastatic TCC and 52 non-TCC carcinomas were collected. The avidin-biotin-peroxidase method was utilized, using polyclonal antiuroplakin as the primary antibody on 95% ethanol-fixed, Papanicoloau-stained direct smears.


RESULTS
Twenty-five of 27 metastatic TCC cases (93%) were found to stain positively for uroplakin with a superficial membrane/microluminal staining pattern. A few cells with diffuse membranous staining also were noted in 48% of the positive metastatic TCC cases. The superficial membrane/microluminal staining pattern was not observed in any of the non-TCC carcinomas. However, approximately 6% of these cases (3 of 52 cases) did show rare tumor cells with diffuse membranous staining.


CONCLUSIONS
The application of uroplakin antibodies to 95% ethanol-fixed FNA direct smears has improved the sensitivity of the antibody for metastatic TCC while maintaining a specificity comparable to that of paraffin-embedded tissue. The authors believe that these antibodies have diagnostic potential in cytopathology in the evaluation of metastatic TCC.
Xu
X
X
Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Sun
T T
TT
Gupta
P K
PK
Zhang
P
P
Nasuti
J F
JF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001707:Biopsy, Needle; D002295:Carcinoma, Transitional Cell / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D010641:Phenotype; D001749:Urinary Bladder Neoplasms / Q000378:metabolism* / Q000473:pathology; D060170:Uroplakin II
D014408:Biomarkers, Tumor; D008565:Membrane Proteins; D009363:Neoplasm Proteins; C554658:UPK2 protein, human; D060170:Uroplakin II