Pathology/Lab Coding Alert

Question: The pathologist examines an FNA from a "breast mass" and is unable to provide a definitive diagnosis. Would the appropriate diagnosis be "breast neoplasm of uncertain behavior"?

Texas Subscriber

Answer: You should not use an uncertain behavior code, such as 238.3 (Neoplasm of uncertain behavior of breast) if the pathologist does not provide a definitive diagnosis.

In the scenario you describe, a code such as 611.72 (Lump or mass in breast) would be more appropriate.

Here's why: Uncertain behavior codes are appropriate when the pathologist identifies a neoplasm that exhibits characteristics indicating that it might become malignant. The cells may be undergoing a transformation to malignancy, but the pathologist cannot make a clear distinction between benign and malignant.

If the tumor has an unpredictable behavior, it then fits in the neoplasm of uncertain behavior category. ICD-9 describes these tumors as "histomorphologically well-defined neoplasms, the subsequent behavior of which cannot be predicted from the present appearance."

In other words, 238.3 means that the tumor is uncertain, not the pathologist. You don't want to assign a neoplasm code if the pathologist does not clearly indicate the condition.