Must We Wait for the Pathology to code malignancy?
By Erica E. Remer, MD, CCDS
This article was inspired by an article I read by Cynthia Tang and Richard Pinson (https://libmaneducation.com/coding-of-possible-malignancy-diagnoses-when-the-pathology-report-is-pending/). They expressed their concern about Coding Clinic’s advice to code an uncertain malignancy diagnosis when the pathology report was pending (Be aware that their article referenced 2023 Second Quarter, but the question and answer really appeared in First Quarter. I’m a little mortified that I didn’t pick up on this issue when it first appeared!). The question regarded a “liver mass, possibly hepatic cholangiocarcinoma,” and the documentation also indicated that the pathology was still pending.
Coding Clinic advised that this did fall under the purview of ICD-10-CM Official Coding and Reporting Guidelines, Section II.H. (https://www.cms.gov/files/document/fy-2024-icd-10-cm-coding-guidelines.pdf), Uncertain Diagnosis. As we know, this guideline allows for the coding of an uncertain diagnosis qualified with a word like, “probable,” “suspected,” “likely,” or such, if the condition has not been ruled out prior to discharge or demise, on the inpatient side. Coding Clinic recommended assigning C22.1, Intrahepatic bile duct carcinoma in this case.
The idea behind the uncertain diagnosis guideline is that the resources utilized to rule out a condition are similar to the resources used to rule it in. The Diagnosis Related Group (DRG) payment system is based on a statistical model recognizing that a given principal diagnosis, in the context of accompanying secondary diagnoses, predictably costs a certain amount of money to work up and treat. If a patient has an infiltrate and you still believe it is due to pneumonia at the time of discharge, then the insurer paying your institution for a pneumonia DRG is reasonable.
It is interesting to use Simple Pneumonia and Pleurisy as an example. This is a three-tiered DRG (MS-DRG 193, with MCC- RW 1.3235; 194, with CC- RW 0.8190; 195, without CC/MCC- RW 0.6224). Let’s say the provider decides it was acute bronchitis and not pneumonia. That would land in MS-DRG 202, Bronchitis and Asthma with CC/MCC (RW 0.9527) or 203, without CC/MCC (RW 0.6927), depending on the associated secondary diagnoses. If the final diagnoses ended up being cough and fever because pneumonia was ruled out and no alternate explanation was offered, MS-DRG 204, Respiratory Signs and Symptoms, (RW 0.8196) would be assigned. Depending on the comorbidities, Simple Pneumonia and Pleurisy may not be the most favorable DRG, so routinely making an uncertain diagnosis because some administrator suggested you get paid more might not be the best plan.
For many uncertain diagnoses, there may be no way to ultimately determine a definitive diagnosis. There may be no conclusive way to prove it. No gold standard diagnostic criteria, no cultures, no imaging. It may come down to clinical judgment.
However, a mass which gets biopsied is a different story. There is a way to resolve the uncertainty.
We teach our providers to float an uncertain diagnosis of malignancy if that is their (strong) suspicion, so that we can avoid having to query them if the pathology returns positive. My position has always been that this is important to get right for more than landing in a more favorably reimbursed DRG.
The story of the encounter is not accurate or complete if a patient was found to have a malignant neoplasm, but it was not documented and captured. The pathology report should resolve the uncertainty.
In fact, if the provider were to make an uncertain diagnosis of malignancy and the pathology were to return negative, the correct reaction would be to query the provider for clarification to remove the diagnosis, if appropriate. The clinician would need to determine if they still believed there was a malignancy (the biopsy could have missed its mark and be misleading) or if they believe the diagnosis should be amended.
Pinson and Tang point out that it has “always been an HIM and coding practice that coding is not completed or final billed until the pathology report is available for inpatients, particularly to confirm a malignancy diagnosis.” They refer to not coding unconfirmed HIV infection, but I don’t think that is a good analogy. HIV, Zika, COVID-19, and certain identified influenza viruses are only coded as “confirmed cases” but you don’t have to have laboratory proof.
The provider’s assertion that the patient has the condition is sufficient. You are just advised to not code uncertain diagnoses of these conditions.
Is it premature to drop the claim before the pathology results return? Should the institution have a policy that the pathology needs to be reviewed prior to billing? I guess it depends on how long the typical pathology turn-around time is, how good the clinician is at suspecting malignancy diagnoses, and how irritated they will get at receiving a query to potentially reverse their diagnosis.
My opinion is that being branded as having a malignancy has profound implications and it would be preferable to hold encounters with pending pathology to ensure accuracy. If a patient dies, transitions to hospice, or declines a work-up, then an uncertain diagnosis resulting in coding a malignancy without confirmation might be appropriate.
Programming note: Listen to Dr. Erica Remer every Tuesday when she cohosts Talk Ten Tuesdays with Chuck Buck, 10 Eastern.