ICD-10 for pathology cases that fail to yield a definitive diagnosis


Holden, ME
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Greetings ~
Hoping for a discussion/explanation of how you handle ICD-10 coding for the pathologist in your laboratory when a specimen fails to yield a definitive diagnosis.

The official ICD 10 guidelines in Section IV. Diagnostic Coding and Reporting Guidelines for Outpatient Services instructs us that in the absence of a definitive diagnosis we are to report the symptom as the diagnosis. For a pathology lab, this would be the referring physician's clinical diagnosis.

I am trying to reconcile this when the referring clinician submits a specimen for a stated malignancy which is not seen by the pathologist in the specimen and is reported out (by the pathologist) without a definitive diagnosis.

Here is a simple (redacted) example:
TISSUE/SPECIMEN: 1. Voided urine
Voided urine (concentration preparation):
Satisfactory for evaluation.
Negative for High Grade Urothelial Carcinoma.
Transitional cell carcinoma of bladder

If I am to understand the Official ICD-10 Guidelines and advice from APF Pathology Service Coding Handbook, this case would be coded with C67.9 - Malignant neoplasm of bladder, unspecified. However, I am conflicted because that is not representing the results as reported by the pathologist (it could even be argued that this choice of ICD 10 is contradictory to the pathology findings).
It has been brought up that a personal history code could be used, (Z85.51 - Personal history of malignant neoplasm of bladder), but it's very possible that this is not accurate either AND it also poses the question about using a personal history ICD 10 as a primary code (can we also discuss this? lol! maybe not in this thread?).

I am curious, Fellow Pathology Coders - how do you handle coding these kind of scenarios?

Thanks in advance for the discussion!


True Blue
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I am not a pathology coder, but I do agree with the guidance you've cited. If the pathologist hasn't given you a codable definitive diagnosis, then your only choices are to use the diagnosis that the ordering provider has given you, or to query that provider (or review their records if you have access to them) if for some reason that order is unclear or contradictory.

In the example you've given above, the ordering provider has given you a diagnosis. I don't think it's appropriate to assume that the cancer diagnosis is contradictory - they haven't said it's a 'suspected' cancer, and it's possible that provider may have received other pathology results that you're not aware of which confirm the diagnosis. You also can't assume that they meant a history of cancer rather than active cancer because they haven't said so. As I see it, your only options here are to take the provider's word for it, or to query them for clarification.


Atlanta, GA
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Hi All
I bill lab and x-ray ALL the time plus past job experience. Lab companies really hate unspecified dx codes but they do accept them. Also only use Z dx codes if they are considered FIRST listed Z dx codes as last resort. The lab companies can use a sign or symptom R dx code. As example chest xray then use Chest pain R07.89 if supported. But need an idea from doctor order or what searching for by reading the medical record for the day of treatment use the dx block related to illness. As example use dx codes such as K76.89 Other disease related to Liver Disease for creatinine lab test or K59.89 Other Intestinal Ds. or Z12.11 if fecal occult lab test being done if no real patient symptoms. I always give a Z dx code as last dx code. I use a Z13.89 as last dx code or Z code related to encounter for ds coincide with lab.

If doc searching for thyroid ds. lab test I would use dx or E07.89 Disorder for Thyroid Ds. If patient is male and gets a prostate PSA CPT 84153 use the dx N42.9 or N52 or N40 whatever is documented. However you need to get provider give idea what searching for which is on lab requisition or letter he sends back pt or puts this info on pt medical record same day order lab test.

As example pt. got a CPT 86592 syphilis test, I have used dx code A52.9 or A63.8 or A31.8 then use I used as last dx Z11.3 if documentation fits. Also have use last dx Z13.89 or Z01.89 Encounter for disorder or exam instead. Most lab do not accept Z dx code unless it is first listed dx code. You can use past or family history code as last dx but try more definitive or symptom dx codes first
Oh yes dx R78 & R79 blood and dx R82 are for urine but doc needs to say abnormal finding in these differ body fluids

I hope I helped you
Lady T