Papillary urothelial neoplasm with moderate to high-grade cytology.
Includes some former 1973 WHO TCC grade 2 and all grade 3.
Papillae more complex with fusion or confluence.
Loss of cellular polarity, often crowded and overlapping.
Moderate to marked pleomorphism, prominent nucleoli and abundant mitosis, at any level (image A) & (image B).
In cases of tumors with mixed low-grade and high-grade (should be at least 5%) areas, the overall grade is assigned as high-grade.
Presence of invasion should always be thoroughly excluded.
Recurrence rate of 34-74% and progression rate to invasive cancer of 15-40%.