[944] Common Diagnostic Problems in Interpretation of Early Invasive Bladder Cancer: A Consensus Study.

Steven S Shen, Charles C Guo, Jae Y Ro, Rose Anton, Liang Cheng, Omar Hameed, Luang D Truong, Jiaoti Huang, Mark A Weiss, Fan Lin, John R Srigley, Jesse K McKenney, Pheroze Tamboli, David J Grignon, Rafael E Jimenez, Ming Zhou, Gladell P Paner, Patricia Troncoso, Mahul B Amin, Alberto G Ayala. The Methodist Hospital, Houston; UT M.D. Anderson Cancer Center, Houston; Univ. of Indiana, Indianapolis; Univ. of Alabama at Birmingham; Univ. of California Los Angeles; The Urology Group, Cincinnati; Geisinger Medical Center, Danville; Credit Valley Hospital, Mississauga, ON, Canada; Stanford Univ., Stanford; Mayo Clinic, Rochester; Cleveland Clinic; Univ. of Chicago; Cedars-Sinai Medical Center, Los Angeles

Background: Diagnosis of early invasive bladder cancer in biopsy or transurethral resection of bladder tumor (TURBT) specimens is often problematic due to a variety of reasons.
Design: 26 cases of biopsy or TURBT specimens that were initially categorized as “suspicious for invasion” were selected for this study. Three photomicrographs of each case were reviewed by 19 genitourinary (GU) pathologists and 17 senior pathology residents/fellows (PGY3 or above). A uniform answer sheet was provided to participants and each case was recorded as either an invasive or non-invasive cancers. The results were summarized and comparison of diagnosis of each case by GU pathologists and senior pathology trainees was made by Fisher's exact test.
Results: Among the 26 cases of “suspicious for invasion”, 9 and 8 cases were diagnosed as invasive or non-invasive carcinoma respectively by at least 15 of the 19 GU pathologists. The remaining 9 cases were diagnosed as invasive tumors by 42.1% to 73.4% (average 53.8%) GU pathologists. The most common shared features of the 9 invasive carcinomas were: high grade nuclear features, alteration of cytoplasm, subepithelial nests with angulated edges, peritumoral clefting, confluent growth, and dense desmoplasia. The most common shared features that had the least agreement were cases with severe cautery and crush artifact and marked inflammation. In 10 of 26 (38.5%) cases, there was statistically significant diagnostic discordance between GU pathologists and senior pathology residents/fellows (p<0.05), including both over diagnoses and under diagnoses of invasion.
Conclusions: Our study highlighted the significant problems in evaluating early invasive bladder cancer and identified features that are the most helpful to GU pathologists for a more definitive diagnosis of invasion. Furthermore, problems of over- and under-diagnosis are frequent among the senior pathology trainees, necessitating focused training and education.
Category: Genitourinary (including renal tumors)

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 197, Tuesday Morning


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