Had ct scan w/ contrast in march & it showed no accessory spleen. had recent scan w/o contrast that now shows an accessory spleen. which is correct?

No difference: One reader of ct may have overlooked accessory spleen or splenule which can be quite small or did not report it because of lack of importance. The major spleen does most of work for body. Accessory spleen has very minor function. It's only importance if interpreted wrongly as some other mass or if need splenectomy and accessory spleen is left behind. In most cases it is of little importance.

Of no consequence: Some radiologists do not comment on normal variants, such as an accessory spleen, while others feel such findings should be documented. Sometimes it is done so that the referring doctor does not need to call the radiologist if they are confused when they see it. Either way, to you it is of no consequence, except causing unnecessary confusion.