This course will address common but difficult diagnostic problems encountered by the pathologist in everyday practice. Every effort will be made to present cases of common practical value. Participants and faculty will review case histories, examine case images and formulate the diagnosis. A responsive keypad system will be utilized for interactive audience participation. Topics to be covered will include: (1) the spectrum of papillary lesions, (2) differentiating between fibroadenoma and phyllodes tumor, (3) columnar cell lesions, including flat epithelial atypia, (4) diagnosing lobular neoplasia, and (5) the importance of several variants of invasive mammary carcinoma. The unique subtleties and differentiating characteristics of each diagnosis will be highlighted with special emphasis on the benefit and limitations of immunohistochemical markers used in the workup of these breast lesions. Faculty and participants will discuss strategies for managing each patient's case. All participants will receive a comprehensive syllabus with a list of current and classic references for each diagnostic issue addressed to form a solid foundation for use in daily surgical pathology practice as it relates to breast pathology. Pre-registrants will have the ability to view (by virtual microscopy) the images of all cases presented on the USCAP website prior to the meeting. After the meeting, all participants will receive web access to the PowerPoint presentation given at the Annual Meeting along with the text portion of the syllabus for retention.

(LAST SCHEDULED PRESENTATION) This course may be used for CME credits or SAM credits.