10=fine needle aspiration
11=needle aspiration
20=closed percutaneous biopsy/Core biopsy, NOS
21=Core biopsy, small diameter
22=Core biopsy, large diameter
30=Open biopsy, NOS
31=Re-excisional biopsy
32=Incisional biopsy
33=Excisional biopsy
40=Mastectomy, reduction
50=mass or tissue, NOS
90=Unknown
95=Metastatic site only, including lymph nodes only
99=OMIT - implant removal, foreign body removal, no breast tissue, skin only