Pathology/Lab Coding Alert

Question: My question regards coding for keratin stains, specifically S100 and HMB 45, in the process of carrying out a sentinel lymph node biopsy. Breast cancer diagnosis and treatment often depend on this procedure, as do more and more cancer protocols (e.g., melanoma). It is becoming a standard of care that we cannot afford to ignore. Sentinel lymph node biopsy involves serial sectioning of the specimen and the use of special stains at multiple levels. Is it true that the code for the special stains can be reported only once per specimen, regardless of the number of sections evaluated? If so, how are we to capture the extra work and expense involved in the sentinel lymph node biopsy?

California Subscriber

Answer: CPT 2001 introduces a way to code for the sentinel lymph node biopsy by adding sentinel lymph node to the specimen list for 88307 (level V surgical pathology, gross and microscopic examination). Prior to that addition, the sentinel node was reported as 88305 (level IV surgical pathology, gross and microscopic examination, lymph node, biopsy). Some coders even hesitated to report 88305 for the sentinel lymph node when the patient underwent a radical mastectomy because regional lymph nodes are bundled with that specimen (88309, level VI surgical pathology, gross and microscopic examination, breast, mastectomy - with regional lymph nodes). CPT 2001 makes it clear that the sentinel lymph node is considered a separate specimen, and it is afforded a higher level of service due to the work involved.

As you mentioned, in addition to reporting the sentinel lymph node service (88307), you should also code separately for the histochemical staining. This may involve multiple slides from the sectioning of each of several tissue blocks, all from one lymph node. Regardless of the number of slides, report 88342 (immunocytochemistry [including tissue immunoperoxidase], each antibody) only one time per antibody per specimen. The specimen is the sentinel lymph node, not the tissue block. Therefore even though the keratin stain is performed at multiple levels, you can report 88342 only one time.


Answers to You Be the Coder and Reader Questions provided by R.M. Stainton J.R., MD, president of Doctors Anatomic Pathology Services, an independent pathology laboratory in Jonesboro, Ark.