No, you do not necessarily have a case. Depending on the information available to your doctor at the time you were diagnosed and the steps he or she took will determine whether or not you have a case. This information must be "weighed against the applicable medical standard of care." If you received low-level care compared to another medical professional in the same practice, you may have a case. If your misdiagnoses came from a poor standard of care resulting in an injury, you will have to prove this in order to make a worthy claim.