Pathology/Lab Coding Alert

If the new Pap guidelines cause the anticipated explosion of human papillomavirus (HPV) testing, you can expect to see the fallout in both procedure and diagnosis coding.

In addition to the past choices of colposcopy or repeat Pap smear, the Consensus Guidelines for Cervical Cytological Abnormalities published earlier this year add a third choice of HPV testing for the 2 million cervical smears annually classified as atypical squamous cells of undetermined significance (ASC-US).

You can access algorithms for the guidelines at the American Society for Colposcopy and Cervical Pathology (ASCCP) Web site at http://www.asccp.org/pdfs/consensus/algorithms.pdf.

"Identifying ASC-US patients infected with high-risk HPV strains allows improved triage, identifying the subset of ASC-US patients who clearly should proceed to colposcopy," says Edward Wilkinson, MD, immediate past-president of ASCCP and chairman of the consensus guidelines steering committee.

It may also hasten the switch from traditional Pap smear technology to liquid cytology, known as "thin-layer preparation" methodology, because the patient with ASC-US interpretation does not have to return for specimen collection to test for the presence of high-risk HPV, the primary causative agent of cervical cancer. The initial cervical specimen can be "reflexed" for HPV testing. "Using the liquid cytology Pap test and reflexing to the HPV test for ASC-US patients may help avoid unnecessary colposcopy, as well as provide a cost and convenience benefit," Wilkinson says. If a traditional Pap test results in ASC-US classification, the patient must return for additional cervical sampling to proceed with the HPV testing, or return for a repeat Pap smear or colposcopy.

Choose Liquid Cytology Pap Test Code

Already the most common method for Pap tests, the new guidelines may encourage even greater use of thin-layer preparation methodology. "You have to decide which code to use for this service based on whether the Pap test is ordered for diagnostic or screening purposes," says Melanie Witt, RN, CPC, MA, an independent coding consultant based in Fredericksburg, Va., and former program manager for the American College of Obstetricians and Gynecologists' department of coding and nomenclature.

You should report screening Pap tests, ordered in the absence of signs or symptoms of disease, with HCPCS Level II codes (see "Choose Between Two Sets of Liquid Cytology Codes" at left). Physicians generally order these tests with diagnoses such as V76.2 (Routine cervical Papanicolaou smear) or V15.89 (Other specified personal history presenting hazards to health, other). If the doctor orders a Pap test due to presenting symptoms such as abnormal vaginal bleeding (626.6, Metrorrhagia), the test is diagnostic, and you should report it with one of the appropriate CPT codes. Select the proper code within each set based on how the lab performs the initial screening and rescreening, e.g., manual or computer-assisted.

If a screening or diagnostic Pap test shows abnormal results, a pathologist will interpret the smear. "Report this physician service in addition to the original test using a separate code," Witt says. As with the Pap test code, you have to choose the interpretation code based on whether the original test was for screening or diagnostic purposes.

For the interpretation of screening liquid cytology Pap tests, you should report G0124 (Screening cytopathology, cervical or vaginal [any reporting system], collected in preservative fluid, automated thin-layer preparation, requiring interpretation by physician). Bill physician interpretation of any abnormalities found in a diagnostic Pap test using +88141 (Cytopathology, cervical or vaginal [any reporting system]; requiring interpretation by physician [list separately in addition to code for technical service]).

Some payers will reimburse for the Pap specimen collection reported as 99000 (Handling and/or conveyance of specimen for transfer from the physician's office to a laboratory) or for Medicare Q0091 (Screening Papani-colaou smear; obtaining, preparing and conveyance of cervical or vaginal smear to laboratory). "Medicare only pays for Q0091 for screening, not diagnostic Pap tests," Witt says.

Report HPV Following ASC-US

For liquid cytology Pap tests or traditional Pap smears classified as ASC-US, clinicians may order a test to evaluate the presence of high-risk HPV DNA sequences. The lab may conduct the test on the reflexed liquid cytology specimen or may collect a new specimen from the patient. The most common lab method for HPV analysis involves gene amplification, reported as 87621 (Infectious agent detection by nucleic acid [DNA or RNA]; papillomavirus, human, amplified probe technique). Report direct probe HPV tests as 87620 ( papillomavirus, human, direct probe technique).

The new ICD- 9 codes (effective Oct. 1, 2002) do not align with the 2001 Bethesda System for cervical cytology classification, which complicates diagnosis coding to establish HPV medical necessity. The new ICD-9 codes divide ASC-US into two categories: favor benign (795.01, Atypical squamous cell changes of undetermined significance favor benign) or favor dysplasia (795.02, Atypical squamous cell changes of undetermined significance favor dysplasia). Bethesda 2001 eliminates the ASC-US distinction of "favor reactive" or "favor squamous intraep-ithelial lesion (SIL)." Instead, Bethesda 2001 divides the single ASC category into two subcategories: ASC-US and ASC-H (ASC cannot exclude high-grade SIL).

"Although it's not perfect, 795.01 is the best code to describe both ASC-US and ASC-H findings under the new ICD-9 code structure," Witt claims. "You would not want to assign ASC-H to 795.02, which would imply a potentially more severe condition. Nor can you report the finding as unspecified (795.00, Nonspecific abnormal Papanicolaou smear of cervix, unspecified) or nonspecific (795.09, Other nonspecific abnormal Papanicolaou smear of cervix), because it is specific."

"The Bethesda distinction is crucial because the new guidelines recommend the HPV testing option for ASC-US findings, but not for ASC-H findings, which the guidelines recommend for follow-up colposcopy," Wilkinson says.

Regardless of the Pap interpretation, the physician must order the HPV test before the lab can bill it. Labs should inform physicians of the guidelines' alternative to order HPV following ASC-US and provide an option on the requisition form for physicians to order HPV (e.g., 87621) following ASC-US Pap interpretation.

Although the guidelines only require an HPV test that is "sensitive and specific," Digene's Hybrid Capture II (hc2) is the only commercially available HPV DNA assay with U.S. Food and Drug Administration (FDA) approval for reflexed thin-layer preparation specimens, and it is approved only for specimens collected using Cytyc Corp.'s ThinPrep Pap test. With a validation study to ensure comparable sensitivity and specificity, labs may reflex other thin-layer preparation Pap tests, such as PreservCyt, PREP, SurePath or CytoRich for HPV testing. Report hc2, which detects nucleic acid targets and amplifies the signal, using 87621.

If the physician orders the HPV test following an initial Pap smear that was not thin-layer preparation, the patient must return for specimen collection. The FDA-approved method for collecting such a specimen is the Digene Cervical Sampler. Some payers may cover sample collection (99000) for the second specimen in addition to the code for the test, e.g. 87621.

Report Additional Pathology If HPV-Positive

If the patient is negative for high-risk HPV, she should revert to annual Pap testing, according to the guidelines. But if she is positive for high-risk HPV, the physician refers the patient for colposcopy. The pathologist may receive a cervical biopsy specimen from this procedure and report it as 88305 (Level IV Surgical pathology, gross and microscopic examination, cervix, biopsy).

Physicians use the biopsy results to further triage the patient under the new guidelines: Women with confirmed cases of cervical intraepithelial neoplasia (CIN), such as 622.1 (Dysplasia of cervix [uteri]) or 233.1 (Carcinoma in situ; cervix uteri), are treated accordingly, while women with CIN ruled out return to a repeat Pap or HPV test in a year.

Abnormal Paps May Yield Colposcopy Specimen

The new guidelines do not recommend the HPV test for most abnormal Pap tests but suggest immediate colposcopy referral for many other classifications, such as ACS-H, LSIL, HSIL, and atypical glandular cells (AGC). Depending on colposcopic findings, the physician may obtain a biopsy specimen or perform a cervical conization. You should report pathology evaluation of these specimens as 88305 ( Cervix, biopsy) or 88307 (Level V Surgical pathology, gross and microscopic examination, cervix, conization).