The hallmark of the professional is continued development and expanded expertise based on acquisition of new knowledge and refinement of clinical skills. Medical knowledge acquisition is a key component of professional development for fellows in training as well as practicing physicians. New medical knowledge may be acquired via experience/instruction in the clinical setting (clinic, hospital, etc), self-directed or teacher-directed reading, case-based discussions, lecture presentations, recorded enduring presentations (vodcasts, podcasts, etc.), online learning modules, review- and board-type questions/answers, and small-group discussions. All of these methods have value for continued expansion of medical knowledge, and for many learners, a combination of methods is far superior to reliance on one or two methods alone. The following four cases demonstrate the benefit of case-based discussions to further pediatri nephrology fellow education.