Pathology/Lab Coding Alert

Special stains are common ancillary services you’re bound to encounter in pathology or cytopathology reports because they enhance microscopic evaluation of tissue and cellular material. That means you need to know how to correctly code these procedures.

Make sure you capture all the pay your lab deserves by learning the following codes and the specialized rules for reporting special stains.

Limit These 4 Codes to Special Stains

CPT^® provides the following four special stain codes, not including additional specialized immunohistochemistry (IHC) codes that we won’t discuss here:

• 88312 (Special stain including interpretation and report; Group I for microorganisms (eg, acid fast, methenamine silver))
• 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)
• +88314 (Special stain including interpretation and report; histochemical stain on frozen tissue block (List separately in addition to code for primary procedure))
• 88319 (Special stain including interpretation and report; Group III, for enzyme constituents)

Coder tip: Some stains aren’t “special,” so you shouldn’t use one of the preceding codes when you see them listed in the pathology report. These are the routine stains that labs use on every specimen of a certain type.

“The routine stain you’ll see in nearly every pathology report for a tissue specimen is hematoxylin and eosin (H&E),” says R.M. Stainton Jr., MD, president of Doctors Anatomic Pathology Services in Jonesboro, Arkansas.

Categorize Stain Types

You can see from the code definitions that CPT^® categorizes special stains into groups based on the purpose for the stain, as follows:

• Group I for microorganisms (88312);
• Group III for enzyme constituents (88319); and
• Group II for “all other” (88313).

Although the code definitions give examples of stain names (eg. …), what the stain is “for” is the most important piece of information you need to select the correct code.

88312: For instance, the pathology report might mention stains for organisms such as bacteria Helicobacter pylori from a gastric specimen (Steiner stain) or Mycobacterium tuberculosis from a lung specimen (acid fast stain); protozoa such as Plasmodium (Giemsa stain for malaria); or fungi (methenamine silver for yeast infection).

88319: If the pathology report mentions a stain for an enzyme activity, such as NADH or ATPase in a specimen such as muscle or nerve tissue, you should use 88319.

88313: This code’s descriptor designates “all other,” specifying that the code is not for microorganisms (88312), enzyme constituents (88319), or IHC (several codes such as 88342, Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain procedure). Code 88313 stains help pathologists identify features such as iron stores in a bone marrow specimen (iron stain), morphological features like connective tissue and nuclei in a specimen such as liver (trichrome stain), or amyloid deposits in tissue such as kidney (Congo red stain).

Add-On Alert: Clarify Specimen Sources

Pathologists use stains described by codes 88312, 88313, and 88319 on anatomic pathology tissue specimens such as biopsies, cytologic (cellular) specimens such as fine needle aspirations (FNAs), or hematologic (blood) smear specimens. Do not use 88312, 88313, or 88319 for stains on other specimens such as microbiology cultures or frozen tissue.

If the specimen is frozen tissue, use special stain code +88314 in addition to the code for the primary procedure. The CPT^® text note specifies the primary procedure may be one of the following:

• Mohs (17311-+17315, Mohs micrographic technique, including removal of all gross tumor, surgical excision of tissue specimens, mapping, color coding of specimens, microscopic examination of specimens by the surgeon, and histopathologic preparation including routine stain(s) (eg, hematoxylin and eosin, toluidine blue) …);
• Anatomic pathology (88302-88309, Level … - Surgical pathology, gross and microscopic examination …); or
• Intraoperative pathology consultation (88331-+88332, Pathology consultation during surgery… with frozen section(s) …).

Caveat: Even if the specimen is frozen tissue, you should use 88319 if the reason for the stain is to identify enzyme constituents. Do not report +88314 in that case.

Notice 2-Level Unit of Service to Protect Pay

CPT^® provides a text note following each code 88312, 88313, and 88319 that states “Report one unit of [code number] for each special stain, on each surgical pathology block, cytologic specimen, or hematologic smear.” A similar note for +88314 directs you to report one unit “for each special stain on each frozen surgical pathology block.”

These statements identify the unit of service on two levels — the stain and the specimen.

Break it down: Report one unit of the appropriate special stain code for each stain. If the pathologist uses two stains that are separately visible under the microscope, you should list two units of that stain code.

More: Instead of reporting one unit of each stain for each surgical pathology specimen, you should report one unit of each stain for each surgical pathology block.

Process: When pathologists process a tissue specimen, they may divide the tissue into distinct blocks. They then “fix” the blocks with formalin and embed them in paraffin or freeze the blocks. The final step is cutting the blocks into thin slices for viewing under the microscope. The text notes allow you to report the appropriate special stain code once for each block.

Payday: If you miss the instructions for “per stain” and “per block,” you could be leaving vast amounts of money on the table. One unit of 88312 pays $114.55 (Medicare Physician Fee Schedule national nonfacility amount, conversion factor 34.6062). Two 88312 stains on each of three tissue blocks would garner $114.55 x 6 = $687.30.