Gastroenterology Coding Alert

Question: Can I use the morphology of neoplasm codes listed in Appendix A of the ICD-9 manual as diagnosis codes? One of our gastroenterologists removed a polyp during a colonoscopy and said that is was villous adenoma. He said that it is not a benign polyp and should not be reported with a diagnosis code of 211.3 (benign neoplasm of other parts of digestive system; colon). I couldnt find a code for villous adenoma polyp in the standard ICD-9 section, but I did find an M code (M8261/1) for villous adenoma NOS in the appendix. Please clarify this coding situation.

New York Subscriber

Answer: The morphology codes should not be reported as diagnosis codes on a claim, but they can help you figure out the proper diagnosis code to use. The morphology codes are used by pathologists to collect further data on the types of neoplasms that they are analyzing, says Pat Stout, CMT, CPC, an independent gastroenterology coding consultant in Knoxville, Tenn. They should not be used by gastroenterologists for diagnosis codes on medical claim forms.

Your gastroenterologist wanted to make sure the polyp removed was not classified as benign because he thinks it might be malignant, and the appendix can help you locate the correct ICD-9 code to be reported. The morphology code numbers consist of five digits. The first four numeric digits (M8261 in your example) identify the histological type of neoplasm that was found. The fifth digit (/1 in your example) indicates its behavior and has a corresponding ICD-9 neoplasm section(s). The one-digit behavior codes are as follows:

/0 benign (corresponds with ICD-9 neoplasm sections 210-229)

/1 uncertain whether benign or malignant (corresponds with ICD-9 neoplasm sections 235-238)

/2 carcinoma in situ (corresponds with ICD-9 neoplasm sections 230-234)
intraepithelial
noninfiltrating
noninvasive

/3 malignant, primary site (corresponds with ICD-9 neoplasm sections 140-195 and 200-208)

/6 malignant, metastatic site (corresponds with ICD-9 neoplasm sections 196-198)

/9 malignant, uncertain whether primary or metastatic site (corresponds with ICD-9 neoplasm section 199)

Your villous adenoma polyp is classified with a /1 as uncertain whether benign or malignant, which corresponds with ICD-9 sections 235-238 and is where you will find your correct diagnosis code. Look through those sections to find the site of the body that best describes where the neoplasm was found. In your situation, Stout recommends 235.2 (neoplasm of uncertain behavior of digestive and respiratory systems; stomach, intestines, and rectum).