Pathology/Lab Coding Alert

Don’t let neoplastic diagnoses stump you.

When your pathologist reports colon polyp findings to the ordering physician, do you know how to select the correct ICD-10 code from the narrative diagnosis in the pathology report? Missing appropriate ICD-10 codes could lead to payment problems for the physician and treatment problems for the patient.

Drill down to the ICD-10 colon polyp nuances with our experts’ advice in four easy steps.

Step 1: Wait for the Pathology Report

To choose the correct ICD-10 diagnosis code for a colon polyp, you will need to know the polyp behavior. That means correctly interpreting the pathological descriptions used in the report and translating those descriptions into the right category.

“Surgeons may imply what type of polyp it is in an operative report, but they usually defer to the pathology report before making a final recommendation about when the colonoscopy should be repeated,” says Terri Brame Joy, MBA, CPC, COC, CGSC, CPC-I, billing specialty subject matter expert at Kareo in Irvine, Calif. “The path report contains the definitive determination of a colon polyp’s behavior.”

Importance: Correct diagnosis of the polyp determines the appropriate procedure code for the case if it began as a screening colonoscopy, the follow-up interval for colonoscopy, and the patient treatment plan for a polyp that is cancerous or may turn that way.

Step 2: Get to Know Non-Neoplastic Colonic Polyps

If the pathology report doesn’t document the polyp as adenoma, benign, or inflammatory, you should turn to the general code K63.5 (Polyp of colon).

“You should also use K63.5 for a diagnosis of hyperplastic colon polyp,” says R.M. Stainton Jr., MD, president of Doctors’ Anatomic Pathology Services in Jonesboro, Ark. That’s true even if you have greater specificity about the site of the polyp, according to ICD-10-CM Coding Clinic. (2015 Vol 2 No. 2).

Inflammatory or pseudopolyps: Inflammatory polyps often occur in patients with inflammatory bowel disease or ulcerative colitis, but are also found in otherwise normal colon exams, says Glenn D. Littenberg, MD, MACP, FASGE, AGAF, a gastroenterologist and former CPT^® Editorial Panel member in Pasadena, California. With no indication of complications, you should report K51.40 (Inflammatory polyps of colon without complications). The code further extends out to K51.4-- where the fifth and sixth characters will specify the condition with added complications, such as K51.411 (… with rectal bleeding).

Tip: Use an additional code with category K51 to identify manifestations.

Step 3 Master Adenomatous Polyp Codes

Polyps that the pathology report describes as adenomas can be susceptible to developing colorectal cancer, but not all such polyps turn malignant. You might find various terminology in the pathology report that indicates which ICD-10 code you should use.

Benign: If the report describes a benign adenomatous colon polyp such as tubular adenoma or a tubulovillous adenoma, you should turn to D12.- based on the site of the colon, such as D12.3 (Benign neoplasm of transverse colon).

Uncertain: “A villous adenoma of the colon is a more advanced polyp, closer to malignancy with a different glandular structure, and is sometimes a carpet-like polyp,” Littenberg says. Unlike coding for other adenomas, ICD-10 alphabetic index directs you to D37.4 (Neoplasm of uncertain behavior of colon) for villous adenoma.

Combination: Occasionally, you might see a polyp reported as a sessile serrated lesion with greater propensity to CA/ adenoma, which microscopically has some features of a hyperplastic polyp but has a behavior (cancer potential) of an adenoma, Littenberg notes. “These should be coded using the D12.- series based on location.”

It’s also common for patients to have multiple polyps of different morphologies, such as hyperplastic polyps and adenomatous polyps in different locations. If the polyps have different diagnoses, you can report one ICD-10 code for each type of polyp.

History: Because of the potential for malignancy, most insurers will reimburse follow-up and surveillance procedures for patients who have had adenomatous polyps, which you should designate using Z86.010 (Personal history of colonic polyps).

Step 4: Code Malignant Polyps

When a polyp becomes cancerous, the pathologist will identify it as an adenocarcinoma, which is malignant.

The pathology report might describe a polyp as having a distinct area of cancerous cells, using terminology such as “high grade dysplasia” or “carcinoma in situ.” In those cases, you should list the adenocarcinoma using a code such as D01.0 (Carcinoma in situ of colon), depending on the site.

If the cancer has spread beyond the polyp itself, you’ll turn to the appropriate colon cancer code from the category C18 (Malignant neoplasm of colon).