PAX8 and thyroid cancer: Although PAX-8 is also present in renal cancer, thyroid cancers, and pancreatic neuroendocrine tumors [23, 24], TTF-1 is a specific marker for thyroid and lung cancers [25], and a PAX-8 positive, TTF-1 negative adenocarcinoma would exclude thyroid cancer and increase the diagnostic accuracy for gynecologic cancers.