Comprehensive profile of GATA binding protein 3 immunohistochemical expression in primary and metastatic renal...

Transcription factor GATA binding protein 3 (GATA3) has been suggested as a marker of urothelial carcinoma of the bladder and upper urinary tract. Its expression in primary and metastatic renal tumors has not been fully determined. We evaluated GATA3 expression in 47 oncocytomas, 196 primary renal cell carcinomas (RCCs) (71 clear cell, 53 papillary, 21 Xp11.2, 33 chromophobe RCCs, and 18 collecting duct carcinomas [CDC]), and 43 unrelated metastatic RCCs (41 clear cell and 2 Xp11.2 RCC). GATA3 nuclear expression was evaluated in tissue microarrays built from archival tissues using immunohistochemistry. Intensity (0 to 3+) and extent (percentage) of expression were assessed. Several cutoff values (>0%, >5%, and >10%) were evaluated to indicate GATA3 positivity. Among oncocytomas, 9 (19%) of 47 had some degree of nuclear GATA3 expression with median extent of 0% (0%-100%). When using either 5% or 10% cutoff values, 5 (11%) of 47 oncocytomas were positive. In primary RCCs, 6 (3%) of 196 had some degree of nuclear expression with a median extent of 0% (0%-100%). When using either 5% or 10% cutoff values, 2 cases remained positive (1%) (Xp11.2 and CDC). All metastatic RCCs were negative. We found an overall lack of GATA3 expression in primary and metastatic RCCs. GATA3 is expressed in a minority of oncocytomas, Xp11.2-RCC, and CDC. Given GATA3 positivity in upper urinary tract urothelial carcinoma, our findings support a role for GATA3 in the differential diagnosis of primary renal masses and a utility in the interrogation of metastatic tumors of unknown primary in the presence of a renal mass.