At the beginning of these guidelines, we suggested that you need to have a clear idea of what is particularly interesting about the case you are documenting. The introduction is where you convey this to the reader. It is useful to begin by placing the study in a historical or social context. If similar cases have been reported previously, describe them briefly. If there is something especially challenging about the diagnosis or management of the condition that you are describing, now is your chance to bring that out. Each time you refer to a previous study, cite the reference (usually at the end of the sentence). There are many ways to cite references, but the style that we have chosen is simply to put a number in brackets and then at the end of the article list the references in numerical order. This will be described in more detail later, but the important point is to properly cite any other papers or textbooks that you refer to.
Your introduction doesn’t need to be more than a few paragraphs long, and your objective is to have the reader understand clearly, but in a general sense, why it is useful for them to be reading about this case.
It is not unusual to find authors including what they refer to as a "review" of the literature in their case study. By "review", they mean a search and synthesis of the literature. However, these days "review" often has a different connotation. It refers to a well structured and specific search, often with a meta-analysis of the data from the various papers retrieved. Such an exercise would be deserving of a separate paper and would not be paired with a case study. If we have simply done a search for similar cases, and wish to describe them to place our own in context, that is quite appropriate. Furthermore, this information belongs in the introduction of our paper, not in the discussion.
