The number of cases will vary significantly depending on where you are. I don't recall my numbers as a 4th year specifically, but had many more peds, abdominal and SSB cases and much fewer H&N. We had a large surg onc service so I graduated with lots of livers and pancreases.
david stern's post - particularly the last paragraph touched a cord with me, because I have found it to be painfully true as a fellow. I don't believe I really did the cases, even as a Chief and when asked to help an intern do a case during my fellowship, had to "confess" that since I really hadn't ever done the case by myself, didn't feel comfortable doing so.
During my 4th year as a resident on the Pediatric Surgery service I protested and refused to log any cases, feeling that if I wasn't doing the case, or at least 50% of it, or if the attendings were double-scrubbing, it just didn't count. Administration quickly denounced my activities, saying they "were aware" of the problems of lack of independence on that service, but felt unable to do anything about it - so I had to (fradulently) log cases in which sometimes I did little more than cut suture or hold hook.
We had one new attending who liked to give the residents independence - ie, not show up for awhile and tell you to start the case, or to leave in the middle, etc. Scary at first, exhilarating at best, and a wonderful learning opportunity...he was also sanctioned by administration. "We just don't do that here." I always found it curious that the private practice surgeons allowed the residents to do so much more, especially when their income was based on outcome, unlike the salaried university surgeons.
Thank goodness this doesn't occur everywhere and thank goodness I'm not the only one in this boat and it does occur elsewhere. I'm starting to understand perhaps why 100% of recent grads of my program do fellowships...perhaps none of them felt prepared to do general surgery either.