Reporting Path Services Before a Definitive Diagnosis Is Available? Here’s How
Test your knowledge with 4 typical examples. Pathology reporting often unfolds over time. A specimen may arrive, undergo initial gross and microscopic evaluation, and then require additional studies before a final diagnosis can be reached. In some cases, a pathologist may issue preliminary findings or defer a definitive diagnosis until ancillary testing is complete. For pathology coders, this creates an important and recurring question: How should you report services when the diagnosis is still pending? The key principle remains consistent across all pathology workflows: CPT® code assignment is based on the professional and technical services performed, not on whether a final diagnosis has been rendered at the time of reporting. The Pathology Workflow: Diagnosis Often Requires Multiple Steps Unlike many other specialties, pathology frequently involves a staged diagnostic process. After a specimen is received, it is accessioned and processed for evaluation. The pathologist typically performs a gross examination, followed by tissue processing, sectioning, staining, and microscopic review. For many specimens, this process is sufficient to reach a final diagnosis. However, in other cases, additional studies are required to clarify findings or establish diagnostic certainty. These may include: As a result, pathology reports may include preliminary interpretations while additional testing is pending. Important: Report the Work Performed, Not Diagnostic Certainty One of the most important rules in pathology coding is that CPT® code selection is driven by the work performed, not by whether the pathologist has issued a final diagnosis. For example, you report surgical pathology specimens requiring both gross and microscopic evaluation using the appropriate CPT® code based on specimen type and level of complexity, regardless of whether the diagnosis is benign, malignant, atypical, or deferred pending additional studies. Common surgical pathology level codes include: The correct code assignment is determined by CPT® guidelines for specimen type and complexity. The presence of phrases such as “atypia,” “suspicious for malignancy,” or “pending additional studies” does not alter the CPT® code assignment for the specimen examination itself. Report Ancillary Testing Separately When Supported Pathology cases frequently require additional ancillary studies to reach a definitive diagnosis. These services may be separately reportable when medically necessary, appropriately documented, and not bundled under CPT® or payer-specific rules. Examples of these ancillary studies include: Report flow cytometry services based on the number of markers and components evaluated; codes include: Report molecular pathology services using CPT® molecular pathology codes, including Tier 1 and Tier 2 codes from the 812xx-814xx series (Molecular pathology procedures… ). You can report cytogenetic studies using codes from the 882xx series (Cytogenetic studies… ). Each service must be supported by documentation of medical necessity and reported according to CPT® and payer-specific guidelines. Differentiate Preliminary and Deferred Diagnoses Pathologists may issue preliminary findings when additional testing is required to establish diagnostic certainty. For example, a lymph node biopsy may initially show an atypical lymphoid proliferation. Additional flow cytometry and immunophenotyping may be required to determine whether the process represents a reactive condition or lymphoma. Similarly, a skin biopsy may demonstrate atypical melanocytic proliferation requiring immunohistochemical staining before the provider can render a final diagnosis. In these situations, coding is based on the services performed at each stage of the diagnostic workup. The coder’s role is not to interpret or finalize the diagnosis but to accurately capture all reportable laboratory services. Look for Ancillary Studies One of the most common areas of confusion involves additional testing ordered after initial evaluation. For example, a breast biopsy may reveal atypical cells on hematoxylin and eosin (H&E) staining. To further characterize the lesion, a provider may order immunohistochemical stains. You would report the surgical pathology examination with a code based on specimen type and complexity, such as 88305 (Level IV - Surgical pathology, gross and microscopic examination … breast biopsy). Then, if medically necessary, you may report ancillary testing separately using 88342 (Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain procedure), and you can code additional stains using +88341 (Immunohistochemistry or immunocytochemistry, per specimen; each additional single antibody stain procedure (List separately in addition to code for primary procedure)). The same principles apply to special stains, molecular studies, flow cytometry, and cytogenetic testing when supported by documentation and not otherwise bundled. Work Through These Common Pathology-Pending Scenarios Try your hand at the following examples: The provider evaluates a core needle breast biopsy using gross and microscopic examination. You’ll report this using 88305. The provider identifies atypical ductal proliferation and orders immunohistochemical stains to further classify the lesion. When supported by documentation, codes for ancillary testing may include: A colon polyp is submitted following screening colonoscopy and evaluated using gross and microscopic examination. You’ll report this using 88305 (Level IV - Surgical pathology, gross and microscopic examination … Polyp, colorectal). Your pathologist may perform additional levels (step sections). These are included in the primary surgical pathology service and are not separately reportable. However, if additional ancillary testing is required, such as immunohistochemistry, you may report it separately when appropriate (such as 88342). Multiple prostate biopsy cores are submitted due to elevated PSA. You’ll report this with 88305 (Level IV - Surgical pathology, gross and microscopic examination … Prostate, needle biopsy) Initial evaluation may show a focus suspicious for adenocarcinoma, requiring immunohistochemical studies. Ancillary testing for this may be reported with: A skin lesion biopsy is evaluated using gross and microscopic examination. You’ll report this using 88305. The pathologist identifies atypical melanocytic proliferation and orders immunohistochemical stains for further classification. When supported by documentation, you’ll report ancillary testing with: Note These Documentation Considerations for Pathology Coders Accurate pathology coding depends on complete and specific documentation. Coders should ensure reports clearly support: Understanding how these elements connect is essential for accurate charge capture and compliant reporting. Identify Charge Capture Considerations Because pathology workflows often extend across multiple days, the provider may perform ancillary testing after the initial case review. Common areas where services may be missed include: Heads up: You need to be familiar with laboratory charge reconciliation workflows to ensure you capture all reportable services before claim submission. Stay Current With Compliance Considerations Although pathology coding is driven by services performed, documentation must support medical necessity for all ancillary testing. Not every stain or molecular study is separately reportable. Each service must be justified clinically and supported by documentation in accordance with CPT® and payer guidelines. Coding should always reflect actual work performed, not anticipated results or expected diagnostic outcomes. The Bottom Line A pending diagnosis does not mean a pending charge. That’s because pathology services are reported based on the professional and technical work performed, not on whether a definitive diagnosis has been reached at the time of reporting. By focusing on specimen type, documented work performed, and properly supported ancillary testing, pathology coders help ensure accurate reimbursement, compliant reporting, and integrity across the laboratory revenue cycle. Suzanne Burmeister, BA, MPhil, Medical Writer and Editor
