The Kansas Histopathology Cases (KHC) is an online educational activity organised by ESP. The scope is to advance the diagnostic skills for pathologists. It consists of 10 rounds. During each round participants receive 5 cases, with minimal clinical information and 1 histopathology image. From the received information and image they need to provide their most preferred diagnosis. The cases are rare and/or difficult and thus it is not easy to reach a diagnosis. After the end of each round, the correct diagnosis for each case is disclosed, along with a handout. The handout includes a clinical exercise for the most convenient way to approach the case, and some suggestive literature for further study.