IMMUNOHISTOCHEMISTRY, PAX-8

What this test checks

Detects PAX-8 transcription factor, expressed in kidney, thyroid, and Müllerian (ovarian/uterine) tumours. Used to identify cancers of these organs when they spread to other sites.

Why do people get this test?

PAX-8 is one of the best markers for identifying kidney, thyroid, and gynaecological cancers in metastatic settings — helping oncologists find the cancer's origin and choose appropriate treatment.

When you should consider this test

• When investigating cancer of unknown primary — especially in women
• When classifying metastatic tumours possibly from kidney, thyroid, ovary, or uterus
• As part of gynaecological cancer or renal cancer diagnostic panels

How to prepare

No preparation needed — performed on biopsy or surgical tissue.