Exponential progress in identifying new diagnostic molecular markers has occurred in recent years. Correctly applying these new markers in surgical pathology may 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-oriented 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, bladder, kidney, and testis, will be analyzed for key histological features, mimics, major differential diagnoses, possible pitfalls, and subsequent clinical significance. Specific dilemmas will be discussed such as identifying a small focus of prostatic adenocarcinoma and its mimics; distinguishing prostatic adenocarcinoma from urothelial carcinoma; classifying the histological variants of infiltrating urothelial carcinoma and assessing the depth of invasion. Additionally, special attention will be placed upon differential diagnoses among renal tumors and the percentage estimation of different components of testicular mixed germ cell tumor.

Emerging biomarkers, such as AMACR, PIN4, CA9, PAX2, PAX8, smoothelin, OCT3/4, SOX2, SALL4, glypican 3, and others, 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 encouraged and appreciated. A syllabus reviewing diagnostic features with a comprehensive reference list will be provided to registrants at the meeting. After the meeting, all participants will receive web access to all the histological images used during the live lecture (original complete presentation) along with the text portion of the syllabus.

Upon completion of the course, you will be able to: 1) understand frequently encountered diagnostic dilemmas in the 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.

This course may be used for CME credits or SAM credits.