A female patient present with a hard mobile lump in her right breast. Which investigation would be most helpful in making the diagnosis

Needle biopsy: Histology can be obtained under local anaesthesia using a springloaded core needle biopsy device. Cytology is obtained using a 21G or 23G needle and 10-mL syringe with multiple passes through the lump with negative pressure in the syringe. The aspirate is then smeared on to a slide, which is air dried or fixed Ref: Bailey and love 27th edition Pg no : 864