Why should i have surgery if my biopsy was negative? the results of my needle biopsy were negative, but my doctor still wants to operate to take out the lump. why?

Biopsies : Biopsies are not always accurate. Unfortunately the results depend on the position of the needle. Cancer is not visible if it is microscopic and the physician performing the biopsy can only use their expertise as much as possible. When biopsies are negative or inconclusive, excisional biopsies are recommended which remove a bigger piece of tissue thus translating to a better chance of obtaining a true answer as to the diagnosis.

Ask him: Difficult to know from the information provided. The best think is to ask your surgeon or get 2 nd opinion.

Biopsy: You should ask your doctor to explain. I can only speculate that perhaps the pathology results did not explain the abnormality(discordance). In other words, if you have an actual mass, the path results(benign or mailgnant) must be able to account for the mass. If it is just 'benign breast tissue', that is not a sufficient explanation for a mass, and re-needle biopsy or excision is needed.