Otolaryngology Coding Alert

Question: What is the diagnostic difference between a neoplasm of uncertain behavior and a neoplasm of unspecified nature?

New Jersey Subscriber

Answer: You should think of uncertain behavior as the pathologist's determination, and unspecified as the documentation's incompleteness. If your otolaryngologist's documentation doesn't specify whether the lesion is benign or malignant, you should use an unspecified diagnosis. On the other hand, a pathologist must reach the clinical determination that a specimen's behavior is uncertain.

You may use an unspecified diagnosis when you're prescheduling a patient's surgery. Suppose a patient presents with a suspicious oral lower lip lesion. Prior to biopsying the lesion, you call the patient's insurer to precertify the surgery. The insurer requires a diagnosis for precertification. Because no pathology report is available, you should use 239.0 (Neoplasms of unspecified nature; digestive system). After the biopsy, the pathologist determines the neoplasm is malignant. When you file the surgery with 40490 (Biopsy of lip), you submit a final diagnosis of 140.4 (Malignant neoplasm of lower lip, inner aspect).

But suppose the pathologist can't determine whether the lesion is benign or malignant. The benign tumors are undergoing malignant transformation. So, he can't make a firm distinction as to the neoplasm's diagnosis without further study. He notes "uncertain behavior" on his pathology report. In this case, you should assign 235.1 for neoplasm of uncertain behavior.