Interpretation of VIA Ė Negative Ė Columnar epithelium appearing white
Columnar epithelium appearing white:
Columnar epithelium appears white immediately after application of acetic acid. This is due to the blanching (shrinkage) of the subepithelial blood vessels as a result of the effect of the acetic acid.
The white colour fades away after a few seconds, and the columnar epithelium regains its original red colour. This blanching is normal and should not be considered as VIA-positive.
Sometimes, indistinct transparent acetowhite patches are visible on the columnar epithelium. These diffuse transparent acetowhite patches are suggestive of squamous metaplasia occurring on the columnar epithelium and should be considered as VIA-negative.