Pathology/Lab Coding Alert

Check out this case study to see if your coding is on point.

Physicians may order lymph node biopsies to aid in diagnosing conditions such as cancer, infections, or immune maladies such as sarcoidosis.

Your lab’s work will depend on the type of biopsy specimen collected. Pathologists may receive a sentinel lymph node to see if cancer has spread, an excised lymph node for diagnosis, or a less-invasive needle specimen from a lymph node. The latter may be from a needle-core biopsy or a fine needle aspiration (FNA) biopsy.

Each of these lymph-node specimen types leads to a different set of CPT^® codes to describe the pathologist’s work. Read on for advice centered on FNA lymph-node pathology exam coding.

Tip 1: Distinguish Different Needle Specimens

To get to the proper code family for a FNA lymph-node pathology exam, you need to determine whether the pathologist used a fine needle to extract an aspirate of fluid containing cellular material as opposed to extracting a core of tissue using a large needle.

If your pathologist examines a lymph node core needle biopsy, the appropriate code for the work is 88305 (Level IV - Surgical pathology, gross and microscopic examination, … Lymph node, biopsy …). On the other hand, if the pathologist evaluates a lymph-node FNA specimen, you should report 88173 (Cytopathology, evaluation of fine needle aspirate; interpretation and report).

Tip 2: Understand Related FNA Codes

Although 88173 describes the pathologist’s evaluation and diagnosis of the FNA specimen, CPT^® provides several other codes you may need to use to describe your pathologist’s work before they get to the final diagnosis step.

Extraction: A surgeon may extract the FNA specimen and submit it to the lab, but sometimes a pathologist may perform the extraction, typically without guidance. If that’s the case, you need to know the following two codes:

• 10021 (Fine needle aspiration biopsy, without imaging guidance; first lesion)
• +10004 (… each additional lesion (List separately in addition to code for primary procedure))

Similar pairs of codes in the range 10005-+10012 exist for FNA extraction with imaging guidance by ultrasound (US), fluoroscopy, computed tomography (CT), or magnetic resonance (MR).

Adequacy: Before performing the full pathology exam, the pathologist will typically take a quick look at the specimen to ensure that it contains “adequate” cells for diagnosis. This involves examining the fluid for the quality and quantity of cells in the aspirate that could provide relevant diagnostic information for the patient’s condition. The check takes place while the patient is still on the table so that another FNA extraction pass can occur if needed. The following codes describe this service:

• 88172 (Cytopathology, evaluation of fine needle aspirate; immediate cytohistologic study to determine adequacy for diagnosis, first evaluation episode, each site)
• +88177 (… immediate cytohistologic study to determine adequacy for diagnosis, each separate additional evaluation episode, same site (List separately in addition to code for primary procedure))

Tip 3: Master Units of Service

The biggest pitfall for pathology FNA coding is failing to get the units of service right. Avoid downcoding or upcoding by learning the following units:

• For extraction (+10004-+10012 and 10021), the unit of service is the lesion.
• For adequacy (88172, +88177), the unit of service is the evaluation episode of fluid from a single unique site. Evaluation episode refers to one service when the pathologist examines fluid from a single site for adequacy, i.e., whether or not the fluid is from one extraction “pass” or multiple “passes” from the same site. A pass refers to sticking the needle into the lesion and withdrawing fluid one time.
• For a pathology exam (88173), the unit of service is the anatomic site. Although the code definition does not state this information, a note following the code states, “Report one unit of 88173 for the interpretation and report from each anatomic site, regardless of the number of passes or evaluation episodes performed during the aspiration procedure.”

Let’s look at a lymph-node FNA case to clarify how to use these codes.

Example: Here are the steps you might see in an FNA lymph-node case for a breast cancer patient:

• The pathologist withdraws fluid from a right axillary lymph node using a fine needle and deposits the sample in the appropriate container.
• The pathologist also performs an FNA extraction from an internal mammary (parasternal) lymph node, withdrawing fluid in two passes placed in two separate containers.
• Next, the pathologist examines the fluid from both FNA sites for adequacy and determines the need to perform another extraction from the initial right axillary node.
• Following the second right axillary node extraction, the pathologist evaluates that fluid for adequacy, finding it adequate for evaluation.
• After the patient is no longer on the table, the pathologist evaluates the adequate specimens from the right axillary lymph node and the parasternal lymph node using ThinPrep methodology and reports the findings.

Correct coding for the above case is as follows:

• FNA extraction for right axillary lymph node: 10021. Even though the pathologist performs another FNA extraction from this node after finding the initial specimen inadequate, you should not report +10004 or another unit of 10021. That’s because the work involves a single lesion and takes place during a single surgical session.
• FNA extraction for parasternal lymph node: +10004. Because this is the second lesion sampled by FNA in the same surgical session, you should use the add-on code, not another unit of 10021. Note that an additional extraction pass does not warrant +10004 x 2, because the unit of service is the unique lesion.
• Adequacy check for right axillary lymph node: 88172 and +88177. Code 88172 describes the evaluation with “inadequate” findings, while +88177 describes the second evaluation episode from the same site.
• Adequacy check for parasternal lymph node: 88172.
• Pathology exam of adequate right axillary lymph node FNA specimen: 88173.
• Pathology exam of adequate parasternal lymph node FNA specimen: 88173.

Tip 4: Don’t Double-Dip Procedure Codes

Another common pitfall in FNA case coding is adding distinct procedure codes for services that are included in the FNA codes themselves.

For instance: Because the pathologist noted evaluating the FNA specimen using ThinPrep technique, you may be tempted to add 88112 (Cytopathology, selective cellular enhancement technique with interpretation (eg, liquid based slide preparation method), except cervical or vaginal)) to the list of payable codes. However, that would be wrong. Although 88112 is the appropriate code for a non-gynecological ThinPrep cytology exam, you should not additionally report the code in this case. National Correct Coding Initiative (NCCI) edits bundle 88173 with 88112 and other non-gyn cytopathology codes such as 88104 (Cytopathology, fluids, washings or brushings, except cervical or vaginal; smears with interpretation). Code 88173 describes the FNA exam, regardless of the cytology method used.

Exception: If the pathologist used a special stain, such as a cytokeratin (CK) immunohistochemistry stain, you could additionally report the stain using 88342 (Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain procedure)

Intraoperative: Because the FNA adequacy check involves reporting findings during surgery, some coders are tempted to add a consultation code such as 88329 (Pathology consultation during surgery). Again, NCCI bundles 88329 as a column 2 code for 88172, so you should not list both codes for the same specimen service. In other words, reporting the adequacy-check findings during surgery is part of the 88172 service; the pathologist is not performing a separate intraoperative pathology consultation.

Ellen Garver, BS, BA, Contributing Writer