Pathology/Lab Coding Alert

Pathology and laboratory coders have disagreed whether diagnostic tests should be reported with the final diagnosis or the signs and symptoms that prompted the test. "It has been difficult for coders to know what to do because of conflicting information in writing," says Barbara J. Cobuzzi, CPC, MBA, CHBME, president of Cash Flow Solutions Inc., a medical billing firm in Lakewood, N.J. CMS has decided that the final diagnosis should be reported if the pathologist determines the diagnosis based on the test.
 
"It is crucial that the ICD9 Code be assigned correctly because the diagnosis must indicate medical necessity for a procedure to be covered," Cobuzzi says. To clarify which ICD-9 code should be assigned when billing diagnostic test procedures, CMS issued Program Memorandum AB-01-144. These guidelines became effective Jan. 1, 2002, in preparation for compliance with the Health Insurance Portability and Accountability Act (HIPAA), which requires most health plans to report diagnoses using ICD-9 by Oct. 16, 2002.
 
The memo clarifies the coding principle of reporting a diagnosis to the highest level of certainty, unless the ordered test was a screening test, or the findings were incidental or unrelated to the symptoms that prompted the test. In other words, the proper ICD-9 code may be based on the results of the test, not the reason for the test, in some circumstances.

Physician Must Make the Diagnosis

The results of a test can be reported as the diagnosis only if they are interpreted by a physician, according to the CMS memo. This is significant for pathology and laboratory coders because some lab procedures necessarily entail a pathologist's interpretation, while others do not.
 
"The biller may get a charge ticket with a description of the presenting signs and symptoms along with the test results, but he or she must know whether a physician assigned the final diagnosis before that code can be used," Cobuzzi says. "This becomes a compliance issue, and policies and procedures must be in place to ensure that the biller has that information."
 
Questions and answers reprinted in the CMS memo from Coding Clinic for ICD-9-CM, by the American Hospital Association, illustrate this point. The examples demonstrate that when a pathologist evaluates surgical specimens, such as a skin lesion or breast mass, it is appropriate to report the specific diagnosis resulting from the pathologist's examination. If the pathologist diagnoses fibroadenoma of a breast mass,  report 217 (benign neoplasm of breast) rather than a less specific code, e.g., 611.72, lump or mass in breast.
 
Other examples in the CMS memo indicate that the results of lab tests can be reported as the diagnosis only if a pathologist authenticates the test results. If a cytology report signed by a pathologist indicates bladder transitional cell carcinoma in a urine specimen submitted due to hematuria (599.7), the lab should report 188.9 (malignant neoplasm of bladder, part unspecified).
 
However, for laboratory tests that do not involve pathologist interpretation, such as a urine culture (87088) or complete blood count (CBC) (85022-85025), the laboratory should not report a final diagnosis, e.g., anemia (285.9) for low hemoglobin and hematocrit CBC results. The lab should instead report the signs and symptoms submitted by the treating physician as the diagnosis. The treating physician interprets the results in light of other clinical findings and assigns the final diagnosis.

Report the Final Diagnosis When Known

The CMS transmittal states, "If the physician has confirmed a diagnosis based on the results of the diagnostic test, the physician interpreting the test should code that diagnosis. The signs and/or symptoms that prompted ordering the test may be reported as additional diagnoses if they are not fully explained or related to the confirmed diagnosis."
 
"This direction clarifies that the most specific ICD-9 code available should be linked to the CPT code for billing purposes," Cobuzzi says.
 
For example, if a skin biopsy from a patient's arm is sent to a pathologist for evaluation, the service is reported with 88305 (level IV - surgical pathology, gross and microscopic examination, skin, other than cyst/tag/debridement/plastic repair). If the pathologist determines that the specimen is a malignant melanoma, the correct diagnosis is 172.6 (malignant melanoma of skin, upper limb, including shoulder, arm).
 
On the other hand, according to the CMS memo, if the results of the diagnostic test were normal or did not provide a diagnosis, the coder should report the signs and symptoms that prompted the test. The ordering physician is responsible for providing the reason for the test when it is ordered, and that information should be documented in writing in the medical record even if the test is ordered by telephone.
 
For example, a patient complains of frequent thirst and episodes of weakness. Suspecting diabetes or kidney disorders, the physician orders a comprehensive metabolic panel (80053), with the presenting symptoms listed on the requisition form as the reason for the test. If the findings of the metabolic panel are normal, report the symptoms that prompted the tests. The appropriate ICD-9 codes are 783.5 (polydipsia, excessive thirst) and 780.79 (other malaise and fatigue, asthenia NOS).
 
Even if the ordering physician had written phrases on the requisition such as "suspected," "rule-out" or "probable" diabetes, it would not be appropriate to code diabetes (250.xx) because the diagnostic test did not confirm the diagnosis.
 
What about findings that are incidental or unrelated to the signs or symptoms that prompted the test? According to the CMS memorandum, "Incidental findings should never be listed as a primary diagnoses." It also states, "unrelated and co-existing conditions/diagnoses may be reported as additional diagnoses." In other words, if a diagnostic test turns up an unrelated condition but does not provide a diagnosis related to the signs and symptoms that prompted the test, coders should still report the signs and symptoms as the primary diagnosis, Cobuzzi says. "The unrelated condition can only be reported as a secondary diagnosis," she says.

Diagnosis Coding for Screening Tests

Screening tests are the one exception to the preceding rules for diagnosis coding. According to the CMS transmittal, "When a diagnostic test is ordered in the absence of signs/symptoms or other evidence of illness or injury, the physician interpreting the diagnostic test should report the reason for the test (e.g., screening) as the primary ICD-9 diagnosis code."
 
"Coders need to understand that if any signs and symptoms prompted the test, no matter how vague, the test is diagnostic rather than screening," Cobuzzi says.  "A screening test is defined as a test in the absence of any signs and symptoms. For screening tests ordered as part of a routine physical, the lab or pathologist must report the appropriate screening V code, regardless of the results of the test. This is a clear departure from what some coders have done in the past, in the absence of direction from CMS."
 
For example, a patient receives a routine Pap screening in an annual visit to her ob/gyn. The patient reports no problems, and the physician notes no signs or symptoms to indicate a suspicion of cervical abnormalities. However, the Pap smear returns abnormal cell findings.  
 
"Regardless of the results, report V76.2 (special screening for malignant neoplasms, cervix) for low-risk patients, or V15.89 (other specified personal history presenting hazards to health) for high-risk patients as the primary diagnosis," Cobuzzi says. The CMS memo clarifies that "The results of the test, if reported, may be recorded as additional diagnoses." The abnormal findings could be reported as a secondary diagnosis with 795.0 (nonspecific abnormal Papanicolaou smear of cervix).

Use ICD-9 Codes for Specificity

All of these instructions about whether to report signs and symptoms or the final diagnosis assume an understanding of how to report ICD-9 codes to the highest degree of specificity. CMS transmittal AB-01-144 also provides a refresher on these coding principles.
 
Most ICD-9 codes are comprised of three-, four- or five-digit numbers. Three-digit codes are often category headings, with subdivisions underneath them that have an additional number or two following a decimal to make the numbers either four or five digits. "When the three-digit code is a category heading, it should never be reported as a diagnosis because a more specific code is available," says Stacey Hall, RHIT, CPC, CCS-P, director of corporate coding at Medical Management Professionals in Knoxville, Tenn. "This is true even if the condition is not clearly defined in the medical record, in which case one of the 'unspecified' codes would be used." The unspecified codes are often xxx.9 for four-digit codes, or xxx.x0 for five-digit codes.
 
For example, a sputum specimen from a patient with pneumonia is sent to the lab for bacterial culture isolation and identification (87070, culture, bacterial; any other source except urine, blood or stool, with isolation and presumptive identification of isolates).
 
If no organism is isolated and identified, the correct ICD-9 code remains 486 (pneumonia, organism unspecified), and further testing may be ordered. In this case, the three-digit code is reported because the condition is not subdivided into more specific four- or five-digit codes.
 
If the culture is identified as Streptococcus, Group B, based on the original culture and further testing for definitive identification (87077, culture, bacterial; aerobic isolate, additional methods required for definitive identification, each isolate), the correct diagnosis code is 482.32 (pneumonia due to Streptococcus, Group B). "This diagnosis must be reported to the fifth digit, which is the highest degree of specificity," Hall says. Code 482 cannot be reported alone because it is the heading for "other bacterial pneumonia." Code 482.3 cannot be reported alone because it is the heading for "pneumonia due to Streptococcus." If the isolate had been identified simply as Streptococcus, not Streptococcus Group B, it would still be incorrect to report 482.3. Report 482.30 (pneumonia due to Streptococcus, unspecified), Hall says.