Coding Clinic, Second Quarter 2002, page 7, states “if the sentinel node is positive, a complete axillary node dissection is usually carried out.” When a sentinel node biopsy is done followed by a modified radical mastectomy, should code 40.23, Excision of axillary lymph node, be assigned for the sentinel node biopsy, along with code 85.43, Unilateral extended simple mastectomy? A “simple mastectomy with excision of regional lymph nodes” is an inclusion at code 85.43.
When a sentinel node biopsy and a modified radical mastectomy are performed during the same operative episode, assign only code 85.43, Unilateral extended simple mastectomy. In this case, the sentinel biopsy is not coded separately, because the modified radical mastectomy includes excision of regional lymph nodes. A modified radical mastectomy involves the removal of the entire breast, nipple/areolar region, including the axillary lymph nodes.
Sentinel lymph node biopsy is a diagnostic tool, in which one to three lymph nodes are removed for histopathologic evaluation. The biopsy is done to determine whether the malignancy has metastasized to the axillary lymph nodes. If the sentinel nodes are negative, the need for the more invasive “axillary dissection” is eliminated.