[946] Long-Term Clinical Outcome of Inverted Urothelial Papilloma Including Cases with Focal Papillary Pattern: Is Continuous Surveillance Necessary?

Jay P Maxwell, Cheng Wang, Andrew Kulaga, Asli Yilmaz, Kiril Trpkov. Calgary Laboratory Services and University of Calgary, Calgary, AB, Canada

Background: Inverted papilloma (IP) of the urinary tract is a benign urothelial neoplasm. A controversy, however, exists regarding the need for continuous cystoscopic surveillance, because there are conflicting reports regarding the potential of IP for recurrence and progression. Additionally, it is uncertain if IP with focal papillary pattern (mixed IP/urothelial papilloma morphology) have different clinical outcome than the traditional IP.
Design: We retrieved all cases with a diagnosis of IP from our institutional information system between 01/2000 and 12/2009. All cases with a previous history of higher grade urothelial neoplasm or diagnostic ambiguity were excluded. We identified 35 de novo ('primary') IP, including 3 cases with mixed (IP/urothelial papilloma) features, which represented the study cohort. 34/35 were consecutive routine cases seen in our centralized urology and uropathology practice for the region and only 1 case was from our consult files.
Results: The average patient age was 60 years (range, 26-88), with a male/female ratio of 1.9/1. IP were located in the bladder in 86% (30/35) patients. In 14% (5/35) patients, the primary location was in the urethra (4 male; 1 female). Focal papillary architecture was identified in three patients, age 51, 52 and 78 years (2 male; 1 female). The greatest dimension of the IP, based on the gross description, ranged from 0.1 to 3 cm. The IP with mixed morphology measured 0.8, 1.5 and 3 cm in greatest dimension. The follow-up ranged from 11 to 132 months (mean 66; median 68). Only one 81-years old patient with an initial diagnosis of IP had a recurrent IP diagnosed after 9 months (both with traditional IP morphology). No recurrence or progression was documented in any other patients with an initial diagnosis of IP (traditional or mixed). Of note, the only patient with recurrence had an initial IP that measured only 0.3 cm in greatest dimension, which raises the possibility of incomplete initial resection. Two subsequent biopsies of this patient at 21 and 32 months were negative for bladder tumor.
Conclusions: The absence of progression of IP on long-term follow-up in this study argues strongly against the need of continuous surveillance for patients in which: 1.) the diagnosis is established using strict diagnostic criteria, 2.) the completeness of the resection can be ascertained and 3.) when no previous or synchronous urothelial malignancies are documented. Rare IP with mixed morphology seem to follow the same benign course as the traditional IP.
Category: Genitourinary (including renal tumors)

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 142, Wednesday Afternoon

 

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