Pathology/Lab Coding Alert

Question: What distinguishes a single sentinel lymph node from a single lymph node for coding purposes? I noticed that they appear under different CPT Codes .


Tennessee Subscriber


Answer: Although each specimen that you mention is a single lymph node, the pathologist processes a sentinel node differently from a lymph node biopsy. The additional work involved in the sentinel node explains why this specimen earns an 88307 (Level V -- Surgical pathology, gross and microscopic examination, sentinel lymph node), while a lymph node earns 88305 (Level IV -- Surgical pathology, gross and microscopic examination, lymph node biopsy).

The sentinel node(s) are the first-draining node(s) of a regional lymph-node basin -- the first place cancer cells would lodge if traveling through the lymphatic system. Sentinel nodes entail more careful study for occult metastases. The process involves serial sectioning and histochemical staining techniques to identify micrometastases, which have been associated with recurrence of the disease.
 
Examination of a sentinel node typically involves four to five paraffin blocks prepared from a single lymph node, with multiple serial sections taken at various levels of each block for H and E staining. Don't code the multiple blocks and slides separately -- the sentinel node is 88307 because it involves more blocks and slides than an 88305 lymph node biopsy.

Don't miss: Sentinel node exams often involve special stains that are not included in 88307. For instance, the lab may stain multiple slides from various levels of sectioning with a histochemical stain such as S100. You can separately report this service as 88342 (Immunocytochemistry [including tissue immunoperoxidase], each antibody). Regardless of the number of slides, only report one unit of 88342 when the lab only looks at one antibody stain.