Follow-Up Protocol for Bladder Villous Adenoma
For isolated villous adenoma without coexistent carcinoma, complete surgical excision is curative and routine cystoscopic surveillance beyond standard post-resection evaluation is not required, as recurrence has not been documented in pure villous adenoma cases during long-term follow-up. 1, 2
Risk Stratification Based on Pathology
The follow-up intensity depends critically on what accompanies the villous adenoma:
Pure Villous Adenoma (No Malignancy)
- Complete surgical resection is curative with excellent prognosis 1, 2
- No recurrence or progression to invasive adenocarcinoma occurred in patients with isolated villous adenoma during mean follow-up of 9.9 years 2
- Two patients with pure villous adenoma treated by non-radical excision showed no evidence of recurrence at mean follow-up of 4.6 years 1
- After complete resection, follow-up cystoscopy at 3 months post-resection is reasonable to confirm complete excision, then discharge from routine surveillance 1, 2
Villous Adenoma with In Situ Adenocarcinoma Only
- Favorable prognosis even without radical treatment 1
- No recurrence in two patients with villous adenoma and only in situ adenocarcinoma treated by non-radical excision 1
- Follow-up cystoscopy every 3-6 months for first 2 years, then annually for 5 years 3
Villous Adenoma with Infiltrating Adenocarcinoma
- This represents aggressive disease requiring radical cystectomy with pelvic lymph node dissection 1, 2
- Two of three cases with infiltrating cancer developed distant metastases despite radical surgery 1
- Post-cystectomy surveillance should follow muscle-invasive bladder cancer protocols: urine cytology, liver function tests, creatinine, and electrolytes every 3-6 months for 2 years, then as clinically indicated 3
- Chest, abdomen, and pelvis imaging every 3-6 months for 2 years based on recurrence risk 3
Villous Adenoma with Coexistent Urothelial Carcinoma
- This rare combination requires surveillance protocols for the urothelial component 4
- One documented case showed progression from in situ urothelial carcinoma to sarcomatoid urothelial carcinoma following partial cystectomy 1
- Follow high-grade urothelial carcinoma surveillance: cystoscopy and urinary cytology every 3 months for first 1-2 years 3, 5
- Upper tract imaging every 1-2 years for high-grade tumors 5
Critical Pitfalls to Avoid
Inadequate sampling is the most dangerous error - one-third of villous adenomas harbor coexistent malignancy that may be missed on superficial biopsy 1, 2. Complete transurethral resection with thorough pathologic examination of all tissue is mandatory 1.
Do not assume benign behavior without complete histologic evaluation - coexisting infiltrating adenocarcinoma is present in 33% of cases and portends aggressive course with metastatic potential 1.
Villous adenoma cannot be diagnosed reliably by cystoscopic appearance alone - there are no specific morphologic findings on imaging or endoscopy that distinguish it from other bladder lesions 4.
Special Considerations
- Villous adenomas express colonic epithelial markers (CK20+, CK7 variable, CDX2+, CEA+) distinguishing them from urothelial neoplasms 4, 1, 2, 6
- These lesions have predilection for urachus, dome, and trigone of bladder 2
- In patients with bladder augmentation using intestinal segments, neoplasia risk increases and routine endoscopic surveillance should be performed 6