<prompt> Best definitive investigation for carcinoma breast is ?BiopsyFNACUSGMammography  <response>: . CorecutTrucut biopsy is done under local anaesthesia. It gives clear histological evidence and also confirms DCIS FNAC can not confirm DCIS. This allows proper neoadjuvantprimary chemotherapy, receptor status of the tumour. Wide bore needle biopsy with vacuum is also used. Excision biopsy is done only when FNAC is inconclusive and a facility for frozen section is not available. Incision should be planned in such a way that it will be included in eventual mastectomy. ref:SRB;s manual of surgery,ed 3,pg no 478 