[903] Novel Markers of Squamous Differentiation in the Urinary Bladder

Wenbin Huang, Sean R Williamson, Qiu Rao, Antonio Lopez-Beltran, Rodolfo Montironi, John N Eble, David J Grignon, Muhammad T Idrees, Xiao-jun Zhou, Shaobo Zhang, Lee Ann Baldridge, Noah M Hahn, Michael O Koch, Liang Cheng. Indiana University School of Medicine, Indianapolis, IN; Nanjing Medical University Affiliated Nanjing Hospital (Nanjing First Hospital), Nanjing, China; Nanjing University School of Medicine, Nanjing, China; Cordoba University, Cordoba, Spain; Polytechnic University of the Marche Region, United Hospitals, Ancona, Italy

Background: Pure squamous cell carcinoma and urothelial carcinoma with squamous differentiation often comprise high stage and high grade tumors and are thought to be associated with a poorer prognosis and response to therapy compared to urothelial carcinoma without divergent differentiation. Therefore, recognition of a squamous component is important in guiding prognosis and therapy. However, accurate discrimination between urothelial and squamous components by morphologic features can sometimes be arbitrary. We aim to investigate expression of MAC387, desmoglein-3, and TRIM29 in pure squamous cell carcinoma and urothelial carcinoma with squamous differentiation, and determine whether these markers have utility as diagnostic biomarkers for squamous differentiation.
Design: Eighty-four cases (1992–2011) were retrieved from participating institutions including 51 pure urinary bladder squamous cell carcinomas and 33 urothelial carcinomas with squamous differentiation. Staining with immunohistochemical antibodies against MAC387, desmoglein-3, and TRIM29 was performed.
Results: MAC387, desmoglein-3, and TRIM29 demonstrated a positive reaction in pure squamous cell carcinoma in 51 (100%), 46 (90%), and 48 (93%) cases, respectively. Urothelial carcinoma with squamous differentiation cases showed positive reactions for MAC387, desmoglein-3, and TRIM29 in the squamous component for 32 (97%), 26 (79%), and 32 (97%) cases, respectively. In the urothelial component, labeling was seen in 10 (30%), 3 (9%), and 22 (67%) cases, respectively. MAC387 demonstrated a sensitivity of 99% and a specificity of 70% for squamous differentiation, while desmoglein-3 yielded sensitivity of 86% and specificity of 91%. No urothelial component showed >10% labeling for desmoglein-3. TRIM29 labeling showed sensitivity of 95%, but poorer specificity of 33%.
Conclusions: MAC387 and desmoglein-3 are reliable diagnostic markers for supporting the morphologic impression of squamous differentiation in urinary bladder carcinoma. Desmoglein-3 shows high specificity. Labeling for TRIM29, while frequently present in areas of squamous differentiation, is less specific and also labels areas with urothelial differentiation.
Category: Genitourinary (including renal tumors)

Monday, March 4, 2013 1:00 PM

Poster Session II # 180, Monday Afternoon


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