Diagnosis with Multiple Morphology Terms

Rule K. When no single code includes all diagnostic terms, use the numerically higher code number if the diagnosis of a single tumor includes two modifying adjectives with different code numbers.

When a single neoplasm is described by two modifying adjectives that have different codes, another type of coding difficulty arises. An example is "transitional cell epidermoid carcinoma," which does not describe two different kinds of carcinoma, but rather a single neoplasm containing elements of both cell types. "Transitional cell carcinoma, NOS" is coded M-8120/3 and "epidermoid carcinoma, NOS" is M-8070/3. When there is no single code that includes call diagnostic elements, coders should use the numerically higher code number, M-8120/3 in this example, as it is usually more specific.