This is an interesting question. If you look at the ICD9 guidelines in the front of the book there are specific rules to follow. First we need to know if the original primary uterine cancer was completely excised or erradicated.
The cancer of the vaginal vault, although seeming recurrent from the uterine cancer, must be coded as 198.82 because it is a secondary cancer. So now once we know if the primary cancer, the uterine cancer, was previously erradicated (usually by removing the uterus) then it becomes a history of code V10.42 (classifiable to the 182.0). If they did not erradicate or remove the uterus and that cancer is still being actively treated, then it is 182.0.
So your coding scenarios can be : V10.42, 198.82; or 198.82, V10.42(both of these are acceptable according to the guidelines); or 182.0, 198.82(if the primary uterine cancer is still being treated).
I just learned about this part of the ICD9 guidelines in a class I took last month...I have been coding for 25 years...just goes to show there is always something new to learn!