Pathology/Lab Coding Alert

Question: Our pathologist received a sentinel lymph node biopsy specimen for a breast cancer patient. During the gross exam, the pathologist examined and teased out a portion of the node, which he processed under sterile conditions, cutting thin sections to send of for molecular diagnostics testing for micrometastasis. The pathologist then examined the remainder of the sentinel lymph node, processing it as two blocks, cutting four levels of each block and performing S100 staining on three to five slides from each level. How should I code the pathologist's work?

Wisconsin Subscriber

Answer: The sentinel lymph node biopsy warrants 88307 (Level V -- Surgical pathology, gross and microscopic examination, sentinel lymph node). For the additional molecular diagnostics preparation work, report 88387 (Macroscopic examination, dissection, and preparation of tissue for nonmicroscopic analytical studies [e.g., nucleic acid-based molecular studies]; each tissue preparation [e.g., a single lymph node]). For the immunohistochemistry (S100) staining, you can report two units of 88342 (Immunocytochemistry [including tissue immunoperoxidase], each antibody) for some payers.

Pick surgical pathology level: Sentinel lymph node biopsies require additional resources and work beyond a typical lymph node biopsy, so you have to be sure to select 88307 for a sentinel node instead of 88305 (Level IV -- Surgical pathology, gross and microscopic examination, lymph node biopsy).

Don't miss molecular diagnostics prep: CPT 2010 added two codes to capture additional tissue prep work that a pathologist performs when preparing a select portion of a specimen for molecular diagnostics testing. Your scenario describes such a service, so you should capture your pathologist's additional work by reporting 88387.

Garner special stain pay: You should always report special stains in addition to the primary code for the surgical pathology service when your pathologist examines specialstain slides to aid in diagnosing the patient's condition. In the case of this sentinel lymph node biopsy, the pathologist examined at least 26 immunochemistry-stained slides, based on the number of blocks, levels, and slides you mentioned in the case. But because the 88342 code definition states, "per antibody," you should not list 88342 based on the number of slides. Because the unit of service for surgical pathology is the specimen, correct coding has always required one unit of 88342 per antibody per specimen -- until now.

The CCI Policy Manual version 15.3 states, "If it is medically reasonable and necessary to perform the same stain on more than one specimen or more than one block of tissue from the same specimen, additional units of service may be reported for the additional specimen(s) or block(s)." In your case, because the pathologist performed immunohistochemistry staining on slides from two distinct blocks, you can report 88342x2, according to this CMS instruction.

Caution: You should check with other payers to see if they're abiding by this Medicare change. If so, you can report multiple units of 88342 for a single specimen when the pathologist examines antibody-stained slides from multiple blocks.