Pathology/Lab Coding Alert

The addition of sentinel lymph node to the specimen list for CPT 88307 (level V surgical pathology, gross and microscopic examination; sentinel lymph node) in CPT 2001 has made coding and reimbursement for sentinel lymph node biopsy easier. Fast becoming a standard of care for some cancers, the procedure should be reported with 88307, in addition to other codes that describe processing of the biopsy tissue, such as special stains. To capture appropriate reimbursement for a sentinel lymph node biopsy, pathology coders need to be familiar with the components of the procedure and the unit of service for each part.

Although the addition of sentinel lymph node to the 88307 specimen list is a step in the right direction, it does not fully account for the process involved, says Lena Spencer, MA, HTL (ASCP), HT, QIHC, a histotechnologist at Norton Healthcare in Louisville, Ky.

Melanoma: A Clinical Example

Increasingly, physicians use sentinel lymph node biopsy to detect the spread of melanoma (skin cancer) or breast or other cancers, says Matthew McCoy, MD, director of anatomic pathology at Methodist Hospital, a part of Park Nicollet Group in St. Louis Park, Minn.

A patient presenting with a suspicious mole of the skin (238.2) would first undergo a punch biopsy or small excisional biopsy at the physicians office. The pathologist receives the specimen for diagnosis, reporting the procedure as 88305 (level IV surgical pathology, gross and microscopic examination, skin, other than cyst/tag/debridement/plastic repair). The physician schedules a followup surgery using the pathology results. For a patient with invasive melanoma of Clarks level two to level five with non-palpable lymph nodes, for example, the surgeon may conduct a sentinel lymph node biopsy and wide excision.

The sentinel lymph node biopsy is conducted at the time of wide excision of the lesion. According to McCoy, the cancer site is injected with a radioisotope called technetium 99. This preoperative lympho-scintigraphy allows the radiologist to assess lymphatic drainage from the lesion. The now-radioactive sentinel node is identified using a hand-held gamma detector, and the location is marked for the surgeon. The code for this procedure is 78195 (lymphatics and lymph glands imaging).

The cancer site is then injected with isosulfan blue dye to further assist the surgeon in locating the sentinel node, McCoy says. Code 38792 (injection procedure; for identification of sentinel node) is used to report this service. The surgeon excises the sentinel node or nodes for analysis by the pathologist. Depending on the location of the lesion, we may receive nodes from two different drainage basins, he says.

The pathologist receives the sentinel node and carries out the gross and microscopic examination for a lymph node biopsy, which is coded 88307. If more than one sentinel lymph node is submitted, each is a separate specimen and is reported using 88307. Evaluation of the sentinel lymph node involves much closer examination for micrometastases than a regular lymph node biopsy (88305, lymph node, biopsy). Evaluating the sentinel node involves other procedures that are separately reportable, such as special stains.

Typically, the wide excision of the melanoma lesion is conducted in the same operative session as the sentinel lymph node biopsy. The pathologist receives the skin specimen for biopsy evaluation and reports 88305 (... skin, other than cyst/tag/debridement/plastic repair) in addition to the code for the sentinel node.

Because the architecture of the sentinel nodes from metastatic melanoma is not easily analyzed with frozen sections, no immediate results are available to the surgeon, McCoy says. For this reason, if the sentinel lymph node biopsy reveals metastasis requiring regional lymph node resection, it usually must be scheduled at a later time. At that time, the pathologist evaluates the regional resection and reports it as 88307 (level V surgical pathology, gross and microscopic examination, lymph nodes, regional resection).

Coding Detection of Occult Microscopic Metastases

Evaluation of the sentinel lymph node for micrometastases involves procedures that are separately reportable in addition to 88307 for the sentinel lymph node biopsy.

According to Spencer, We may have four to five paraffin blocks prepared from the sentinel node specimen. For each block, we cut serial sections, and pull off five slides at predetermined intervals for H and E [hematoxylin/eosin] staining. The multiple blocks and slides are not separately reportable, but are bundled with the original 88307 (... sentinel lymph node). From the same serial sectioning of each block, we pull two slides at predetermined intervals for histochemical staining with S100. For these stains, we report 88342 (immunocytochemistry [including tissue immunoperoxidase], each antibody) one time, even if we have two slides per block by four or five blocks.

Again, because the specimen is the unit of service, 88342 is not coded separately for each slide, only for each antibody.

Coders should not think the addition of sentinel lymph node to the 88307 specimen list in CPT 2001 means all services are encompassed by this code. Although this clarifies the fact that a sentinel node is a separate specimen, and acknowledges the level of work done in the examination, the code does not describe all the processes in a sentinel lymph node biopsy. To receive full reimbursement for sentinel lymph node biopsy, coders must accurately report all of the procedures involved.