Pathology/Lab Coding Alert

Question: The pathologist examined an esophageal biopsy from an esophagogastroduodenoscopy (EGD) procedure. The narrative diagnosis is “stromal tumor.” What is the appropriate ICD-10-CM code?

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Answer: To find the best code choice, look up “tumor” in the ICD-10-CM index, then look for “stromal” indented under that term.

The trick is that you won’t find “esophageal” indented under “stromal.” That’s because an esophageal stromal tumor is considered part of the gastrointestinal tract, so you must look under the term “gastrointestinal” indented under “stromal to find “esophagus.” Once there, you’ll see that the code is C49.A1 (Gastrointestinal stromal tumor of esophagus).

You’ll also notice that under “gastrointestinal,” the word “malignant” is indented, and “esophagus C49.A1 also appears under the “malignant” subheading, which means that C49.A1 describes a malignant tumor.

You don’t mention documentation regarding behavior in the pathology report, but if you did have evidence of a stromal tumor with different behavior, you shouldn’t use C49.A1. Indented under “stromal” and under “gastrointestinal” you’ll find entries for “benign” D21.3 (Benign neoplasm of connective and other soft tissue of thorax) and “uncertain behavior” D48.1 (Neoplasm of uncertain behavior of connective and other soft tissue). If the report designates such behavior, you’ll need to use one of those codes instead of C49.A1.

Do this: Once you think you’ve identified the correct code in the alphabetic index, always turn to the tabular list to make sure you have the correct code by reading additional information listed there. For instance, a note under D48.1 indicates that the code is appropriate for stromal tumors of uncertain behavior of the digestive system. A note for the D21 family also indicates that the code includes stromal tumors.

Finding C49.A1 might trip you up if you recall that characters subsequent to the initial character are (almost) always numeric. In fact, you’ll sometimes find an alpha character in the fourth position when digits 1-9 are already in use in that position. That’s why you’ll find C49.A- following C49.9- codes.