Hemangioblastomas & PAX8: A Surprising Twist for Neuro Pathologists

You're a detective in a hospital, trying to solve a puzzle called "hemangioblastoma" (HB). This brain tumor can look a lot like a kidney cancer (clear cell renal cell carcinoma) that's spread to the brain. Both have clear cells and can be linked to a condition called Von Hippel-Lindau syndrome. To solve this puzzle, doctors often use a test called immunohistochemistry, which looks for certain markers in the cells.One marker, called PAX8, is usually seen in kidney cancers but not in HBs. However, recently, some HBs have shown up as PAX8-positive, causing confusion. A study of 23 brain HBs revealed that about 40% of these tumors could be PAX8-positive, and this positivity is often weak and only in certain spots. This new finding is important. It means doctors need to be aware that some HBs can be PAX8-positive. To avoid making the wrong diagnosis, they should use a wider range of markers in their tests, such as CD10, Inhibin-α, PAX2, S100, and anti-Renal cell carcinoma antibody.