The market for health care systems supporting physicians and improving their daily routine is steadily growing. The development of these systems requires handling medical knowledge and process knowledge. One promising knowledge management technique that has been applied in various medical assistant systems is Case-Based Reasoning (CBR). This paper presents selected work from the history of "CBR in Medicine", clarifying that several systems already have been developed in the past, but the medical domain also still provides new problems and challenges, where a CBR-approach can be profitably applied. Currently, we are developing a CBR-based component, able to retrieve medical documents in written text form and to convert them into new patterns like a DICOM Structured Report. The component will be integrated in our existing transparent gateway for distributed data access to enable the collaboration of several health care organizations.