The cases are pretty easy. If you can do the practice cases sent out by USMLE you will be fine. They give you the correct diagnosis if you run the right tests. For example, I ordered a RUQ ultrasound on a patient with classic gall bladder symptoms. The ultrasound report described all the findings typical for cholecystitis and then said at the bottom "Impression: acute cholecystitis". You just need to know how to get to the diagnosis and then treat it once you've figured it out. Pretty basic stuff. My other cases were: CHF, cystic fibrosis, trichomonas, folate-deficiency anemia, DKA, temporal arteritis, and a few others.
Good luck!
