TVAs are precancerous lesions that have a mixture a villous morphology and tubular morphology, where the villous component is <50% of the lesion, but greater or equal to 25% of the lesion.

TVAs have nuclear changes like those in tubular adenomas and villous adenomas:

• Nuclear elongation; elliptical nuclei,
• Nuclear crowding/pseudostratification.

Morphologic changes include:

• Loss of goblet cells,
• Hyperchromatic ("open") nuclei at the luminal surface.

Tubular morphology:

• Round gland-like structures.

Villous morphology:

• Long finger-like projections; similar in appearance to villi.