NAPSA and oncocytic adenoma: Other tumor types, such as squamous cell carcinoma (0 – 3% [7]), oncocytoma [3], colonic adenocarcinoma (0 – 2% [7]), pancreatic adenocarcinoma (0 – 4% [7]), gastric adenocarcinoma, mesothelioma, ovarian carcinoma (0 – 6% [7]), urothelial carcinoma, prostate adenocarcinoma, and breast adenocarcinoma (0 – 3% [7]), have been described as being negative or very rarely positive for napsin A [3,4,6,7].