Sqad, I don't think I made 'quite an assumption' based on the information contained in the original post (and confirmed by Elliemay's response). You'll also note that I followed this statement with a question mark as I was seeking clarification. That said, I agree that in the absence of more information, your theory may also be correct. It is always difficult to establish the actual content of consultant/patient communication as this info becomes diluted by the time it is communicated via others to Answerbank. However, should the lump be benign then I stand by my original response. Should there be more to the story, then Sqad is correct in that only through removal and biopsy can the lump's true nature be established. The surgeon himself/herself may be making assumptions based on the appearance on the scan as to whether he/she expects it to be malignant or not.
To answer your question Elliemay, if it's removal of the lump only, then this op is usually well tolerated and recovery speedy. If the whole kidney is removed, again recovery is usually good but can take a bit longer (maybe a week in hospital). This is assuming (another assumption!!) that there are no other co-morbidities which would impact on a post op recovery. It's a very common op in my place of work and complications are few.
Foodie x