Pathology/Lab Coding Alert

Focus on diagnosis, too.

Follow the steps performed by the pathologist and lab analyst in this lung-mass case to focus on coding excellence. Get the pay you deserve for every procedure, and cap it off with the proper diagnosis code for the patient.

Break Down the Case

A 48-year-old male patient presents with left upper lung mass. Surgeon performs endobronchial ultrasound guided fine-needle aspiration (EBUS-FNA) on the mass.

Pathologist intraoperatively evaluates FNA for adequacy, and determines specimen adequate for diagnosis.

Lab analyst prepares FNA smears with modified Giemsa and Pap stains, and processes the remainder of the material as a cell block to provide hematoxylin and eosin (H&E) stained slides.

On FNA evaluation of Giemsa/Pap stained slides, pathologist notes pleomorphic cells, some with enlarged nuclei. On H&E stained slides from the cell block, the pathologist identifies glandular cell formations, leading to presumptive identification of non-small-cell lung cancer, type undetermined as squamous or adenocarcinoma.

To further identify tumor type, the lab analyst performs immunohistochemistry (IHC) stains on the cell block for Cytokeratin (CK) 5/6, CK 7, p40, and TTF-1.

IHC results for the case were strongly positive for CK 7 and nuclear TTF-1, but negative for p40 and CK 5/6.

Based on cytology and IHC staining, the pathologist interprets the case as adenocarcinoma of lung.

Assign Procedure Codes

Because the surgeon performs the EBUS-FNA, you should not bill an FNA acquisition code for the pathologist, such as 10022 (Fine needle aspiration; with imaging guidance).

However, you should report the pathologist’s work to check the specimen for adequacy using 88172 (Cytopathology, evaluation of fine needle aspirate; immediate cytohistologic study to determine adequacy for diagnosis, first evaluation episode, each site).

For the pathologist’s exam of the FNA smears Pap and Giemsa-stained slides, you should report 88173 (… interpretation and report). Use just one unit of the code regardless of the number of slides evaluated.

“These are standard stains for an FNA, so you shouldn’t report an additional special stain code for the service,” explains R.M. Stainton Jr., MD, president of Doctors- Anatomic Pathology Services in Jonesboro, Ark.

Capture cell block: When the pathologist examines the H&E stained slides from the cell block, you should bill 88305 (Level IV - Surgical pathology, gross and microscopic examination, … Cell block, any source) to charge for the service. Again, H&E is a standard stain and doesn’t warrant a separate special-stain charge.

IHC is separate: You should, however, separately bill for the IHC stains on the cell block. Based on the reported results (positive or negative), you know that these are qualitative stains. You should report the first, separately identifiable IHC stain on the cell block specimen as a single unit of 88342 (Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain procedure).

Report each additional IHC stain as +88341 (… each additional single antibody stain procedure [List separately in addition to code for primary procedure]). The lab analyst performs four separate IHC stains (CK 5/6, CK 7, p40, and TTF-1), so you should list three units of +88341.

Tip: CPT^® provides a code for a “multiplex” IHC stain (88344, Immunohistochemistry or immunocytochemistry, per specimen; each multiplex antibody stain procedure). But CK 5/6 does not warrant the multiplex code, because the pathologist evaluates the CK 5/6 stain as a unit. To bill the multiplex code, the pathologist must report positive or negative findings for each individual antibody.

Final case charge: Your claim should list 88172, 88173, 88305, 88342, and 3 x +88341.

Focus Diagnosis

Based on the FNA and cell-block studies, the pathologist diagnosed the case as lung adenocarcinoma, which is a primary malignant lung cancer. The surgical note identified the site of the lung lesion as upper left lobe. Given these facts, the appropriate diagnosis code for the case is C34.12 (Malignant neoplasm of upper lobe, left bronchus or lung).