NAPSA and papillary renal cell carcinoma: In addition to the expression of napsin A in lung adenocarcinoma, immunoreactivity for napsin A has also been documented in 5.3 - 48.3% of papillary thyroid carcinomas [3,4], 79.0 - 87.5% of papillary renal cell carcinomas (RCC) [3,4,7], 29.4 - 52% of clear cell RCC [3,4,7], 3.9 - 20.0% of chromophobe RCC [3,4], 5 - 20% of hepatocellular carcinoma [6,7], and 8 - 20% of endometrial adenocarcinoma [3,7].