Gastroenterology Coding Alert

Hint: Your first step is to distinguish non-neoplastic from neoplastic polyps.

Colon polyps are among the most common diagnoses that gastroenterologists see, particularly when performing colonoscopies. In some cases, they are neoplastic (most typically, adenoma), which means an abnormal growth has occurred and there’s a potential for malignancy, and in others, they are non-neoplastic, which are typically comprised of normal tissue or harmless tissue (for example, a hyperplastic polyp). Both conditions require careful diagnosis coding, but you must read the documentation in great detail to choose your ICD-10 code correctly.

Check these guidelines to ensure that you have no issues when submitting your claims for treating colon polyps.

Wait for Path Reports Before Selecting Your Polyp Codes

To choose the correct ICD-10 diagnosis code for a colon polyp, you will need to know whether the polyp is benign or malignant. You will have to correctly interpret the pathological descriptions used in the report to translate those descriptions into the right category. Gastroenterologists 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, as the path report contains the definitive determination of a colon polyp’s behavior.

Tip: The final pathology report will be the determining factor on whether a polyp is non-neoplastic or neoplastic. This differentiation is important in selecting the proper time interval for a follow-up colonoscopy. Although most polyps do not usually turn cancerous, they may cause gastrointestinal problems such as bleeding and obstruction.

Get to Know Your Non-Neoplastic Colonic Polyps

Although they are not neoplasms, hyperplastic polyps in the colon most often occur in the rectal region, and you usually report them with either D12.7 (Benign neoplasm of rectosigmoid junction), D12.8 (Benign neoplasm of rectum), or D12.9 (Benign neoplasm of anus and anal canal).

For hyperplastic polyps, you’ll choose from subcategory D12.x with the fourth digit (0 to 6) specifying the location. You also have K63.5 (Polyp of colon) as a possible code for a polyp of the colon, but keep in mind that this code is less specific.

Inflammatory or pseudopolyps: These 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. In this situation, report K51.40 (Inflammatory polyps of colon without complications). The code further extends out to K51.4-- where the fifth and sixth digits (11 to 19) will specify the condition with added complications.

Check Out These Neoplastic Polyp Classifications

Neoplastic polyps have specific classifications as well. They include:

Adenomatous polyps (APs): This type of polyp can be highly susceptible for developing into colorectal cancer, but not all adenomas turn into cancer. Because of the potential for malignancy, most insurers will reimburse follow-up and surveillance procedures for patients who have adenomatous polyps. Patients with APs are usually designated as having a history of colonic polyps (Z86.010, Personal history of colonic polyps).

Instead of calling it an adenoma, the pathology report may also use one of the three subcategories of adenomatous polyps to describe it. “A tubular adenoma is the most common type of benign but potentially precancerous polyp,” Littenberg says. “A villous adenoma (or villotubular adenoma) of the colon is a more advanced polyp, closer to malignancy with a different glandular structure, and is sometimes a carpet-like polyp. Unlike coding for adenomas, the only ICD-10 code for villous polyps is D37.4 (Neoplasm of uncertain behavior of colon), a subcategory of D37 (Neoplasm of uncertain behavior of oral cavity and digestive organs) describing neoplasm of an uncertain behavior, with the fourth digit (1 to 4) specifying the exact location.”

Combination: Occasionally, a polyp is a reported as a sessile serrated lesion/ 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 AP s in different locations. If the polyps have different diagnoses, you can report one for each type of polyp.

Adenocarcinomas: When an adenomatous polyp becomes cancerous, it is called an adenocarcinoma and is malignant. Sometimes a neoplastic polyp will contain an area of adenocarcinoma. In these reports, the designation may be “high grade dysplasia” (or older term, “carcinoma in situ”). In this situation, you’d report D01.1 (Carcinoma in situ of rectosigmoid junction) and D01.0 (Carcinoma in situ of colon), depending on the location.