Is It Safe to Add Lamina Propria to Pathology Specimens?
Yes, the presence of lamina propria in pathology specimens is not only safe but essential for accurate staging and treatment decisions in bladder cancer. The pathology report should explicitly document whether lamina propria is present and the degree of involvement, as this directly impacts clinical staging and subsequent management 1.
Critical Importance of Lamina Propria in Bladder Cancer Staging
The lamina propria must be present in TURBT specimens to accurately distinguish between Ta (confined to epithelial mucosa) and T1 (invading subepithelial tissue/lamina propria) disease. 1 This distinction is fundamental because:
- T1 tumors (lamina propria invasion) carry significantly higher risks of recurrence (45%) and progression compared to Ta lesions 1
- Without muscularis propria in the specimen, 49% of patients with superficial disease will be understaged, versus only 14% if muscle was present 1
- In the absence of lamina propria, accurate staging becomes impossible and repeat resection is mandatory 1
Clinical Implications When Lamina Propria Is Present
For T1 Disease (Lamina Propria Invasion):
Repeat TURBT is strongly recommended for all T1 tumors, especially when muscularis propria is absent from the initial specimen. 1 This is because:
- 20-40% of patients will have either residual tumor or unrecognized muscle-invasive disease when muscularis propria is not present 1
- After repeat resection, if residual disease is found, BCG immunotherapy (category 1 recommendation) or cystectomy should be offered 1
- If no residual disease is found, intravesical BCG with maintenance for at least 1 year is the preferred treatment 1
Pathology Reporting Requirements:
The pathologist must examine and report on lamina propria presence and involvement, along with lymphovascular invasion when applicable. 1 Key reporting elements include:
- Documentation of whether lamina propria is present in the specimen 1
- Degree of lamina propria involvement if tumor is present 1
- Assessment for lymphovascular invasion, which is associated with worse prognosis 1
Common Pitfalls to Avoid
The most critical error is proceeding with definitive treatment decisions when lamina propria is absent from the specimen. 1 This leads to:
- Understaging in up to 49% of cases 1
- Inappropriate treatment selection 1
- Missed opportunities for curative intervention in muscle-invasive disease 1
Another pitfall is confusing inflammatory changes in the lamina propria with true invasion. 1 The lamina propria normally contains:
- Mixed inflammatory cell infiltrates including neutrophils, lymphocytes, plasma cells, and eosinophils 1
- These inflammatory changes can mimic dysplasia or invasion, requiring expert pathology review 1
High-Risk Features Requiring Aggressive Management
When lamina propria invasion is present with ≥2 high-risk features (hydronephrosis, abnormal examination under anesthesia, lymphovascular invasion, or variant histology), neoadjuvant chemotherapy prior to radical cystectomy should be strongly considered. 2 These patients demonstrate: