Pathology/Lab Coding Alert

Turn to detailed diagnosis code.

Kidney pathology often involves several specialized techniques to reach a final diagnosis. Don’t miss out on the payment your pathologist deserves by failing to report every unique service. Use the following case study to brush up on complete and accurate coding.

Procedure: Surgeon performed a needle core left kidney biopsy for a 68-year-old male patient.

Pathology report:

• At the surgeon’s request, pathologist performs intraoperative pathology consultation for specimen adequacy. Viewing tissue sections on a glass slide in normal saline, the pathologist reports the specimen contains sufficient glomeruli levels for diagnosis.
• Pathologist partitions specimen into sections for light microscopy, immunofluo­rescence, and electron microscopy, flash freezing the latter two portions.
• Pathologist prepares and examines formalin-fixed paraffin-embedded (FFPE) slides stained with hematoxylin and eosin (H&E) for light microscopy. Microscopic evaluation indicates clear cytoplasm in epithelial cells, distinct cell membrane, and stroma with enhanced vascularization.
• Using the same tissue, pathologist prepares and examines additional slides with periodic-acid Schiff (PAS), which identifies glycogen in the “clear” cells, trichrome stain to appreciate changes in glomeruli, and methenamine silver to help evaluate glomerular and tubular basement membranes.
• Using flash-frozen tissue, pathologist prepares and examines immunofluorescent antibody stains for IgG, IgM, IgA, and kappa and lambda light chains. Findings included positive staining of infiltrating immunoglobulins and negative light chain staining.
• Again, using flash-frozen biopsy tissue, the pathologist prepares ultrathin tissue sections stained with toluidine blue and examines one glomerulus and tubulointerstitial area using low to high electron microscope magnification.

Diagnosis: The pathologist identifies the final diagnosis as clear cell renal cell carcinoma (CCRCC).

Validate Consultation Coding

You should report the pathologist’s consultation during surgery to ensure an adequate specimen for diagnosis as 88329 (Pathology consultation during surgery).

Requirements: Before you use this code, you should ensure that the pathologist documents that they have met all the necessary conditions. That means you’ll see evidence of the following items in the pathology report:

• Surgeon requests the consultation.
• Pathologist performs the service while the patient is still in surgery, allowing further surgical action, if needed, based on the pathologist’s findings.
• Pathologist provides a written report to the surgeon.

Not frozen: Because the note indicates that the pathologist viewed fresh tissue sections on a glass slide, you should not use the other intraoperative pathology consultation codes, 88331 (Pathology consultation during surgery; first tissue block, with frozen section(s), single specimen) and +88332 (… each additional tissue block with frozen section(s) (List separately in addition to code for primary procedure)).

Identify Specimen Code

The correct code for the primary procedure in this case is 88305 (Level IV - Surgical pathology, gross and microscopic examination … Kidney, biopsy…).

You should not use the more extensive kidney specimen code, 88307 (Level V - Surgical pathology, gross and microscopic examination… Kidney, partial/total nephrectomy…) for this case.

The 88305 procedure includes the technical work of processing the specimen, and the gross and microscopic evaluation. “H&E staining of slides for light microscope examination is standard and included in the 88305 service,” says R.M. Stainton Jr., MD, president of Doctors’ Anatomic Pathology Services in Jonesboro, Arkansas.

Keep Special-Stain Codes Straight

The pathologist identifies two special stains performed on slides from the FFPE tissue. The special stains identified in the pathology note are PAS and trichrome.

Do this: Report three units of 88313 (Special stain including interpretation and report; Group II, all other (eg, iron, trichrome), except stain for microorganisms, stains for enzyme constituents, or immunocytochemistry and immunohistochemistry) for the special stains.

New: If the pathologist digitizes the slides for off-site analysis, you should additionally report the appropriate slide-digitization code paired with 88313, which is +0757T (Digitization of glass microscope slides for special stain, including interpretation and report, group II, all other (eg, iron, trichrome), except stain for microorganisms, stains for enzyme constituents, or immunocytochemistry and immunohistochemistry (List separately in addition to code for primary procedure))

Units: CPT^® instruction directs you to “report one unit of 88313 for each special stain, on each surgical pathology block, cytologic specimen, or hematologic smear.” Because the pathologist uses three distinct stains, you should list three units of the code. The pathology report does not point to the preparation of multiple blocks, so you don’t need to consider how that would impact coding.

Understand “other:” The 88313 CPT^® code descriptor uses the words “all other” to describe the type of special stains covered by the code. That’s in contrast to the other special stain codes: 88312 (Special stain including interpretation and report; Group I for microorganisms (eg, acid fast, methenamine silver)) and +88314 (Special stain including interpretation and report; histochemical stain on frozen tissue block (List separately in addition to code for primary procedure)). Notice that 88312 mentions methenamine silver, but because the code is for microorganisms, the example is referring to the use of the stain to identify fungi. In this case, the pathologist uses methenamine silver not for microorganism, but to elucidate histologic changes in the tissue.

Capture Immunofluorescence Testing

The pathologist indicates using immunofluorescence for three immunoglobulin classes (IgG, IgM, and IgA) and kappa and lambda light chains for a total of five antibody stains. The report indicates performing this procedure on flash-frozen tissue, which is common for this procedure. Code the service using 88346 (Immunofluorescence, per specimen; initial single antibody stain procedure) for the initial antibody stain, and four units of +88350 (… each additional single antibody stain procedure (List separately in addition to code for primary procedure)).

Beware specimen: Although the pathologist indicates dividing the renal biopsy tissue into different segments for FFPE staining, flash freezing for immunofluorescence, and separate processing for electron microscopy, you still have just one specimen. You should not bill an additional 88305 for the immunofluorescence work.

Separately Bill Electron Microscope Work

For the pathologist’s exam of the tissue using the electron microscope (EM), turn to 88348 (Electron microscopy, diagnostic) to report the work. Even though the report mentions toluidine blue staining, you should not additionally report a special stain code. Toluidine blue is a standard stain for EM tissue preparation, so it’s included in the 88348 service.

Specimen: List just one unit of 88348 for the complete EM study for a single specimen, regardless of the number of slides or whether the pathologist reports a “thick section” check in addition to the thin-section EM work.

Collect the Codes for This Case

The pathologist lists the final diagnosis as clear cell renal cell carcinoma (CCRCC). “Because ICD-10-CM breaks the diagnoses down by laterality, you’ll need to look back in the note and see which kidney the surgeon biopsied to assign the correct code,” says Terri Brame Joy, MBA, CPC, COC, CGSC, CPC-I, product manager, MRO, in Philadelphia.

Dx code: With that information, you can choose the appropriate diagnosis code as C64.2 (Malignant neoplasm of left kidney, except renal pelvis).

Procedure codes: Gathering up all the services documented in the pathology report, you’ll list the following codes for this case:

• 88329
• 88305
• 88313x3
• 88346
• +88350x4
• 88348