Pathology/Lab Coding Alert

Accurate diagnosis coding isn’t an end in itself — it has real-world consequences for medical outcomes as well as physician pay.

Look at the following uterine hyperplasia case to see how missing the diagnosis could sacrifice significant reimbursement for your pathologist.

Study This Hysterectomy Case

The physician sees a 53-year-old patient exhibiting post-menopause uterine bleeding. She is also taking Tamoxifen following early-stage breast cancer surgery and is BRCA1 positive. An ultrasound exam notes uterine thickening. Based on the patient’s history and post-menopausal status, the physician performs a hysterectomy, stating “suspicious for endometrial hyperplasia” on the op report.

Pathology report: The pathologist examines the hysterectomy specimen and notes endometrial gland proliferation (4:1 glandular to stromal elements) and atypical hyperplasia with architecturally focal crowding compared to background. Diagnosis – EIN.

Focus on Final Diagnosis First

The case description throws lots of diagnosis-related terms at you, from symptoms to suspicions. The information includes uterine bleeding, menopausal status, hormone status, uterine thickening, patient history, and suspected endometrial hyperplasia.

Cut to the chase: You should code first the final diagnosis that was the focus of the procedure, whatever other secondary diagnosis codes you might add. “Use the diagnosis from the pathology report instead of basing your code selection on initial specimen and case descriptions,” says Terri Brame Joy, MBA, CPC, COC, CGSC, CPC-I, billing specialty subject matter expert at Kareo in Irvine, California.

Note inclusion terms: The pathology report states a diagnosis of “EIN” and describes “atypical” hyperplasia. Both “EIN” and “atypia” are inclusion terms for N85.02 (Endometrial intraepithelial neoplasia (EIN)), which is the correct diagnosis code for this case.

“According to ICD-10-CM guideline I.A.11, the list of terms under a code are referred to as inclusion terms. They include synonyms for some codes and, when listed under an ‘other specified’ code, indicate conditions represented by that code,” says Leah Fuller, CPC, COC, senior consultant, Pinnacle Enterprise Risk Consulting Services LLC, Centennial, Colorado.

Avoid missteps: Without turning straight to the pathology report final diagnosis, you might have coded the findings of “endometrial thickening” coupled with “suspicion of endometrial hyperplasia” as N85.00 (Endometrial hyperplasia, unspecified) or N85.01 (Benign endometrial hyperplasia). But that would be wrong. You should never code a suspected or “rule out” diagnosis as final. Nor should you code hyperplasia based on the imaging finding of endometrial thickening.

“Physicians don’t necessarily consider the thickening of the uterus ‘abnormal’; in fact, it’s just a monthly ‘ramp up’ for women,” says Sarah Holmes, MAL, CPCO, CMM, HITCM-PP, executive administrator and medical coding and billing instructor at Clayton State University in Decatur, Georgia.

Sidebar: If you hadn’t had a final diagnosis in this case, the most accurate code for the endometrial thickening noted on ultrasound would be R93.89 (Abnormal findings on diagnostic imaging of other specified body structures). Without a final diagnosis, you would additionally report the symptom, N95.0 (Postmenopausal bleeding).

See How Final Dx Impacts Procedure Code Choice

For some pathology specimens, the final diagnosis or the reason for the exam impacts the procedure code you choose. That’s the case for hysterectomy specimens.

Because the diagnosis in this case is a neoplasm (EIN), you should report the hysterectomy exam as 88309 (Level VI - Surgical pathology, gross and microscopic examination … Uterus, with or without tubes and ovaries, neoplastic …).

If you had erroneously reported N85.00 or N85.01 as the diagnosis in this case, the appropriate procedure code would be 88307 (Level V - Surgical pathology, gross and microscopic examination … Uterus, with or without tubes and ovaries, other than neoplastic/prolapse …).

Cost: With a $441.58 reimbursement for 88309 and a $290.69 reimbursement for 88307, making the hyperplasia diagnosis coding error would cost you $150.89 (Medicare Physician Fee Schedule, national facility amount, conversion factor 34.6062).

Be Aware of Diagnosis Details

Coding secondary diagnoses in this case is important for the patient’s follow-up care and for demonstrating medical necessity for the surgical procedure. The referring physician may have assigned these codes or included the information in the narrative diagnosis.

To indicate that the patient was currently taking tamoxifen (an estrogen antagonist, which also increases the risk of endometrial hyperplasia), the medical record should reflect Z79.810 (Long term [current] use of selective estrogen receptor modulators [SERMs]).

The patient would not be taking tamoxifen unless she is estrogen-receptor positive, so according to ICD-10-CM rules, Z17.0 (Estrogen receptor positive status [ER+]) is also appropriate.

Finally, the patient’s BRCA1 positive status makes her susceptible to endometrial cancer, so Z15.04 (Genetic susceptibility to malignant neoplasm of endometrium) completes the picture.