[821] Impact of Second Review of Bladder Biopsies and Transurethral Bladder Tumor Resections (TURBT) with Smoothelin Staining on Pathologic Stage

M Cox, M Quick, W Winham, T Kelly, N Gokden. University of Arkansas for Medical Sciences, Little Rock, AR

Background: The invasion of muscularis propria (MP) is crucial in determining appropriate treatment and prognosis in bladder carcinoma. Smoothelin is a novel marker that has been shown to have high sensitivity and specificity for MP in TURBT and cystectomies. Little data exists on the impact of re-evaluation of bladder biopsies and TURBT material with smoothelin staining and its impact on the pathological stage and patient management. Herein, we re-evaluated small bladder biopsies and TURBT specimens with smoothelin staining and compared results with the original diagnosis, and assess its impact on patient management.
Design: Retrospectively, sections from consecutive 12 biopsies and 86 TURBT samples (total 98 cases-70 high grade, 28 low grade) were reviewed and selected slides were stained with smoothelin. MP was evaluated in H&E slides and the corresponding smoothelin immunohistochemistry (IHC) slide in a double blinded fashion. Grading for the extent of cells with cytoplasmic staining was semiquantitative as: negative (0), 1-25% (1+), 26-50% (2+), >50% (3+).
Results: The total number of cases that had discrepancy with original diagnosis was 21 (21%) [6 biopsy (50%) and 15 TURBT (17%)]. The diagnosis was changed from “MP present” to “MP not present” in 19 cases (negative smoothelin) (6 biopsy, 13 TURBT) (19%) and changed from “MP not present” to “MP present” in 1 case (strong diffuse smoothelin staining). Only in 1 case, the diagnosis was changed from “present/ invasive” to “present/ no invasion”.
Conclusions: A significant number of discrepant diagnoses were identified upon re-review and smoothelin staining of bladder biopsies and TURBT samples. Most discrepancies were overcalling rather than undercalling and were most likely due to misinterpretation of hypertrophic muscularis mucosa for MP. Re-evaluation with smoothelin staining changed the pathologic stage in a substantial number of our patient population.
Category: Genitourinary (including renal tumors)

Tuesday, March 23, 2010 1:00 PM

Poster Session IV # 94, Tuesday Afternoon

 

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