Exponential progress in identifying new diagnostic molecular markers has occurred in recent years. Correctly applying these new markers in surgical pathology could be challenging. This course will provide a review and update of practical diagnostic immunohistochemistry in genitourinary pathology with a focus on solving commonly faced problems. It is designed for general practicing pathologists, pathologists-in-training and pathologists with a special interest in genitourinary diseases.

A case-based and scenario-orientated slide seminar will integrate a systematic clinicopathological and immunohistochemical approach to accurate diagnosis of frequently encountered difficult cases in daily practice. Ten cases, including prostate (5), bladder (2), kidney (2), and testis (1), will be analyzed for key histological features, mimics, major differential diagnoses, possible pitfalls and subsequent clinical significance. Special attention will be placed upon the following: identifying a small focus of prostatic adenocarcinoma and its mimics; recognizing histological variants of prostatic adenocarcinoma; distinguishing primary bladder adenocarcinoma from a secondary tumor; differentiating muscularis mucosae from muscularis propria involved by urothelial carcinoma; distinguishing renal epithelioid angiomyolipoma from renal cell carcinoma; identifying metastatic clear cell renal cell carcinoma; and estimating the percentage of different components of testicular mixed germ cell tumor.

Emerging biomarkers, such as AMACR, CA9, PAX2, PAX8, smoothelin, OCT4, and glypican 3, etc., will be discussed to demonstrate their applications in differential diagnoses and clinical and therapeutic implications. An appropriate panel of antibodies, working algorithms, immunostain interpretations, and potential pitfalls will be emphasized.

Virtual slides, still images, and case histories will be posted on the USCAP website for review prior to the meeting. An interactive style will be used, and inputs as well as questions from the audience will be highly appreciated. All participants will receive a CD containing all the histological images used during the live lecture (original complete presentation) and a syllabus reviewing diagnostic features with a comprehensive reference list.

Upon completion of the course, you will be able to: 1) understand frequently encountered diagnostic dilemmas in genitourinary system; 2) select an appropriate panel of immunohistochemical markers; 3) gain expertise in interpreting immunostains; and 4) avoid or minimize pitfalls. Cautious and well-informed utilization of diagnostic immunohistochemistry will be of significant assistance to your daily practice.

(New Course) This course may be used for CME credits or SAM's credits.