Papillary urothelial neoplasm with distinct low-grade dysplastic features.
More common in men, at trigone or bladder neck region and presents with hematuria (so as all other papillary neoplasms).
Not synonymous with older 1973 WHO grade 1 transitional cell carcinoma (TCC) category.
LGPUC includes mostly former TCC grade 1 and some grade 2.
Some former TCC grade 1 also became PUNLMP.
Associated with mutations in EGFR and HRAS.
Size varies, but generally is visualized as smaller lesions.
Papillae (with fibrovascular core) may variably exhibit branching and fusion.
Mild loss of cellular polarity.
Nuclear rounding, slight size variation and mildly abnormal chromatin (image A) & (image B).
Mitosis is occasional and when present is usually closer to base.
Recurrence rate of 48-71% and progression rate to invasive cancer and death is <5%.