Pathology/Lab Coding Alert

Question: During a renal biopsy procedure for a patient with chronic kidney symptoms, the surgeon called our pathologist to the operating room to evaluate whether the specimen included adequate glomeruli for further examination. The pathologist documented a gross exam, including using a grossing microscope, and reported that the specimen was adequate for further examination. After receiving the kidney biopsy in the lab, the pathologist performed microscopic examination with H&E-stained slides, and also evaluated PAS and trichrome stained slides, reporting the diagnosis as chronic diffuse glomerulonephritis. How should we code this case?

Maryland Subscriber

Answer: The case you describe contains many elements common to renal biopsy cases, and you’ll need to separately code each service identified in the pathologist’s documentation.

To report the intraoperative pathology consultation, you should bill 88329 (Pathology consultation during surgery). Although the pathologist documents using the grossing microscope, the service does not rise to the level of a microscopic frozen-section intraoperative pathology consultation, coded to 88331(Pathology consultation during surgery; first tissue block, with frozen section(s), single specimen).

For the pathology exam of the renal specimen using slides stained with Hematoxylin and Eosin (H&E), you should list code 88305 (Level IV - Surgical pathology, gross and microscopic examination… Kidney, biopsy…).

Although the kidney biopsy pathology exam includes the H&E-stained slides, you’ll need to separately report the work the pathologist performs to prepare and evaluate the Periodic Acid Schiff (PAS) stain and the trichrome stain. These are common stains for kidney biopsy because the PAS stain helps highlight basement membranes, and the trichrome stain highlights collagens, helping the pathologist determine the degree of interstitial fibrosis. Each of these special stains warrants reporting a unit 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).

Opportunity: CPT^® instructions for 88313 state, “Report one unit of 88313 for each special stain, on each surgical pathology block.” That means if the pathologist documents processing the kidney biopsy in more than one block and performing the stains on slides from each block, you may report additional units of 88313.

Dx: An appropriate ICD-10-CM code for glomerulonephritis is N03.2 (Chronic nephritic syndrome with diffuse membranous glomerulonephritis).