Utility of Gata3 in the Diagnosis of Urothelial Carcinoma
Alex Chang, Ali Amin, Peter Illei, Edward Gabrielson, Jonathan I Epstein. The Johns Hopkins Hospital, Baltimore
Background: Distinguishing invasive high-grade urothelial carcinoma (UC) from other carcinomas occurring in the genitourinary tract may be difficult. In men, UC must be differentiated from high-grade prostatic adenocarcinoma and spread from an anal squamous cell carcinoma (SCC).
Design: Immunohistochemistry for GATA3, thrombomodulin, and uroplakin III was performed on a tissue microarray (TMA) containing cores from 35 radical cystectomy specimens with invasive high-grade UC. A TMA with 38 high-grade (Gleason score ≥8) prostatic adenocarcinomas and tissue sections from 15 cases of invasive anal SCC were stained with GATA3. Additionally, tissue sections from 15 cases of pulmonary metastases of UC and a TMA with 25 cases of pulmonary SCC and 5 cases of non-small cell carcinomas of the lung with squamous features were stained with GATA3.
Results: Of the 28 GATA3 positive UCs, 25 (89%) cases showed moderate or strong staining, while 3 (11%) cases had weak staining. All positive GATA3 staining was non-focal with at least 20% of the tumor cells being positive. Of the 7 cases that failed to express GATA3, 5 were positive for thrombomodulin and/or Uroplakin III, while 2 cases were negative for all 3 markers. None of 38 high grade prostatic adenocarcinomas were positive for GATA3. Weak GATA3 staining was present in occasional basal cells of benign prostate glands, in a few benign atrophic glands, and in urothelial metaplasia. Of the 15 cases of anal SCCs, 2 cases showed focal weak staining and 1 case showed focal moderate staining. Weak staining was also rarely observed in the benign anal squamous epithelium. Twelve (80%) of the metastatic UC to the lung were positive for GATA3 with 11 cases showing diffuse moderate or strong staining and 1 case showing focal moderate staining. None of the pulmonary SCC or non-small cell carcinomas with squamous features were GATA3 positive.
|Positive Cases||Negative Cases|
|GATA3||28 (80%)||7 (20%)|
|Thrombomodulin||22 (63%)||13 (37%)|
|Uroplakin III||21 (60%)||14 (40%)|