Pathology/Lab Coding Alert

Fine-needle aspiration (FNA) used for the diagnosis of suspicious lesions is growing rapidly because it is a quick, accurate and inexpensive method of obtaining tissue specimens. That means coders need to be aware of all the components of FNA that a provider might perform, and how to capture each service provided.

The CPT codes for FNA are 88170-88173. Any or all of the codes may be required to accurately report the procedures carried out by a pathologist, depending on the specific needs of the patient, says Lena Spencer, MA, HTL (ASCP), HT, QIHC, a histotechnologist at Norton HealthCare in Louisville, Ky.

The first two FNA codes (88170 and 88171) describe the procedure of aspirating fluid or tissue with a long, slender needle inserted into the lesion. The preparation of smears from the aspirate for cytological examination is included in the code, according to CPT Codes 2000. The difference between the two codes is the location of the lesion. Code 88170 is for superficial tissue (e.g., thyroid, breast, prostate), while 88171 is for deep tissue, with the lesion located (under radiologic guidance).

In our practice, the pathologist typically carries out the superficial aspiration, whether superficial or deep tissue, and reports the appropriate code 88170, while the radiologist usually performs the deep tissue FNA (88171), states Spencer. Different practices may have the pathologist perform all needle aspirations, but even if the radiologist assists, only one physician may report the appropriate FNA code, she continues. Radiology records a separate code if guidance assistance is provided to the pathologist. (This accords with the note following code 88171 in CPT: [for radiologic supervision and interpretation, see 76003, 76360, 76942]). If a second FNA is performed because the first proved inconclusive, or because a diffuse area such as an enlarged thyroid is being tested, then 88170 or 88171 would be reported twice, claims Spencer.

Evaluation of Fine-needle Aspirate

FNA codes 88172 and 88173 describe the evaluation of the fine-needle aspirate. These codes should be reported by the pathologist who performs the evaluation, whether or not that same individual aspirated the tissue and reported 88170 or 88171, says Garnet Dunston, CPC, MPC, president of Dunston Enterprises, a coding and consulting firm in Phoenix, Ariz. According to CPT, both 88172 and 88173 refer to evaluation of fine-needle aspirate with or without preparation of smears.

The difference in the two codes is the extent of the evaluation, says Dunston. The pathologist uses code 88172 to report the immediate microscopic examination of the aspirate to assure the presence of diagnostic material. This is done while the patient stays prepped so that more aspirate can be obtained immediately if the specimen is inadequate, reports Dunston. CPT describes the 88172 evaluation as immediate cytohistologic study to determine adequacy of specimen(s).

Code 88173 describes a distinct evaluation service that should be coded in addition to 88172 if both services are provided, advises Dunston. CPT defines the 88173 evaluation as involving interpretation and report. After adequate specimen is assured and the FNA procedure is complete, the cytologist will prepare smears, and then the pathologist will conduct the definitive examination and interpretation of the aspirate to reach a diagnosis.
That is when code 88173 is used, says Dunston, to report the preparation of smears, evaluation, interpretation, diagnosis and report.

As with the FNA procedure codes (88170-88171), the FNA evaluation codes (88172-88173) should be reported on a per-aspirate basis. If two or three separate aspirates are evaluated before an adequate specimen is achieved, code 88172 should be reported that many times, says Dunston. Similarly, code 88173 should be reported individually for each aspirate requiring separate interpretation and report.

Clinical Example

If a patient presents with a palpable mass in the breast, the pathologist might perform a superficial FNA [88170], and analyze the aspirate for adequacy of specimen [88172], says Spencer. If no cell abnormalities are found to explain the mass, a second aspiration (88170) and evaluation for adequacy (88172) may be conducted. Multiple smears are then prepared by the cytologist and evaluated by the pathologist for diagnosis, interpretation and report (88173), Spencer continues. If the mass is found to be malignant, an excisional biopsy would be conducted by a surgeon and examined, interpreted and reported on by the pathologist (88307, surgical pathology, gross and microscopic examination, breast, excision of lesion requiring microscopic evaluation of surgical margins), she concludes.

Notice that slide preparation is not coded separately for FNA but is included in the 88170-88173 codes since CPT states with or without preparation of smears for each of these codes, says Dunston. Consequently, the number of slides is not relevant to selecting the appropriate code. Also, the cytologists preparation of the smears represents the technical component of the code, and the pathologists interpretation represents the professional component.

The key to correct coding for FNA is to remember that each of the codes 88170-88173 represents a distinct service that should be coded if that service is provided, and that the codes should be applied on a per-aspirate basis, concludes Spencer.