[921] Tubular Adenoma of the Urinary Tract: A Newly Described Entity

Chia-Sui Kao, Jonathan I Epstein. Indiana University School of Medicine, Indianapolis, IN; Johns Hopkins Hospital, Baltimore, MD

Background: Villous adenoma involving the urothelial tract is a well-recognized entity, most commonly occurring in the bladder or urachus. Tubular adenomas (TA) in the urinary tract with the same appearance as those in the colon have not yet been described in the literature.
Design: 4 cases of TA in the urinary tract were identified in our surgical pathology files; all were consult cases. Immunohistochemical stains for GATA3, CDX2, CK20, CK7, and B-catenin were performed in 3 of 4 cases.
Results: This lesion was defined by the presence of a collection of small, round, tubular glands with intestinal-type epithelium showing moderate dysplasia, identical to the histology of tubular adenomas in the colon. None of the cases had any villous component, or would have been excluded from this study. Patients ranged from 37 to 63 years old (mean 45) with a predilection for male gender (M:F = 3:1). A detailed clinicopathologic summary is provided in Table 1. All 3 available cases consistently stained positive for CDX2 and CK20, while negative for GATA3 and CK7. 1 case showed positive (nuclear) B-catenin staining.

Table 1. Clinicopathologic Data Summary
CaseSignificant HistologyAge/SexSiteSize (cm)PresentationFamilial Adenomatous PolyposisFollow-up
1HGD*38MProstatic urethra0.3Urethral polypsNNo recurrence to date
2None (usual TA)37FRight ureterovesical junction0.5Ureteral obstructionYNo recurrence to date
3Dense intraluminal secretions63MBladder1.5Hematuria and concurrent pT1 sigmoid adenocarcinoma with colonic TA with HGD*N2 mos. later with pT3b bladder adenocarcinoma and bladder TA at cystectomy
4Paneth-cell metaplasia41MBladderN/AN/ANRecurrent bladder TAs, 3 and 4 years after initial biopsy
*HGD= high-grade dysplasia

Conclusions: TA of the urinary tract is rare. The positive CDX2, CK20, and B-catenin staining should not be used to determine site of origin. 2 of the 4 patients had concurrent TAs of the GI and urinary tract, raising questions of the relationship between the two. There is a potential for recurrence as seen in one patient, although neither the first nor recurrent TAs had high-grade dysplasia. Current data is limited by the rarity of this entity, but one patient later developed bladder adenocarcinoma, such that close follow-up is warranted for TA of the bladder. There is no association with urothelial carcinoma (in-situ or invasive). Recognition of this entity will encourage further reports and help to better understand the relationship of TA to concurrent and subsequent urinary tract malignancies.
Category: Genitourinary (including renal tumors)

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 205, Tuesday Afternoon


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