Neoplasm of uncertain behavior, site unspecified

This code signifies the presence of an abnormal growth of tissue where the pathologist cannot definitively determine if it is benign or malignant. The specific anatomical location of this neoplasm is not documented or is unknown. It represents a provisional diagnosis requiring further investigation.

Use this code when pathology reports indicate a neoplasm of uncertain behavior, and the documentation does not specify the primary site. This is often an interim diagnosis while awaiting further diagnostic studies or when the origin cannot be determined. It is appropriate when the physician explicitly states "neoplasm of uncertain behavior, site unknown."

• Avoid using this code if a more specific site or behavior (benign, malignant, in situ) is documented.
• Always query the physician for clarification on the primary site if possible, as this code is highly unspecific.
• Do not confuse with neoplasms of unspecified nature (e.g., 239.x), which implies the behavior is unknown, not necessarily uncertain.