Nested Variant Urothelial (Transitional Cell) Carcinoma
Grading / Staging
Grading
- Microcystic carcinoma is considered by some to be definitionally low grade
Staging
- Usual rules apply
- If possible, the extent of lamina propria / submucosa invasion should be reported
- Muscularis mucosae is variable and its involvement does not affect staging
- Generally loose strands of muscle
- Muscularis propria involvement is significant and should be evaluated carefully
- Dense, well defiined bundles of muscle
- Depth of muscularis propria involvement cannot be assessed in transurethral specimens
- Presence or absence of propria should be reported even if not involved
- Lymphatic invasion should be confirmed by immunohistochemistry
