trying to understand pathology report!!

Hi all.... im sure someone here would be able to explain this to me , its been one month now since dad had part of his kidney removed, we have been asking for pathology reports for over 2 weeks now but they keep saying not back yet..to cut a long story short rang surgeon last week and was told they were quering something, anyway took dad back to local gp today and his dr is keen for results saying it should only take 5-6 days anyway local gp called surgeons room and spoke to secretary and was told that the pathology report came back "inconclusive", i mean im not medically trained (lol) but surely there must be a visual difference ( of whatever) to a bengin tumour and a malignant one... im confused as to what it all means, what they are doing now is more testing. Anyway if someone out there has the answer please let me know.Thanks ...mandy