Neoplasm of uncertain behavior of trachea, bronchus and lung

This code signifies the presence of an abnormal growth in the respiratory tract (trachea, bronchus, or lung) where the pathologist cannot definitively classify it as benign or malignant based on current microscopic examination. It indicates that the biological behavior of the lesion is currently indeterminate.

Apply this code when pathology reports describe a pulmonary or bronchial lesion as "atypical," "uncertain malignant potential," "indeterminate," or similar terminology, and further diagnostic workup (e.g., repeat biopsy, molecular studies) is pending or inconclusive. Documentation must clearly state the uncertain nature of the neoplasm.

• Do not use this code if the pathology definitively states benign or malignant; instead, select the appropriate benign or malignant neoplasm code.
• Always sequence this code as the primary diagnosis when the uncertain behavior is the reason for the encounter or admission.
• Review the complete pathology report; if subsequent reports clarify the nature of the neoplasm, update the diagnosis accordingly.