Aims : to explore the real-life challenging clinical cases in the innovative interactive session; to present the cases that have various levels of difficulty and often necessitate a differential diagnosis. This session is led by a discussant that will present the cases to a panel of experts and the audience. The discussant will encourage discussion among the panel of experts, who have never seen the cases, and additionally invite the audience in the reflexion and discussion of the cases presented to explore the various diagnostic and therapeutic options.