Carcinoma in situ of left bronchus and lung

This code signifies the presence of abnormal, non-invasive cancerous cells confined to the epithelial layer of the left bronchus or lung. These cells have not spread beyond their original location and are considered a pre-invasive form of cancer.

Assign this code when pathology reports confirm carcinoma in situ specifically within the left bronchus or lung tissue. Documentation must clearly indicate the non-invasive nature and the precise anatomical location.

• Ensure the pathology report explicitly states "in situ" and specifies the left lung or bronchus.
• Do not use this code for invasive carcinoma of the lung; refer to codes in the C34 series for malignant neoplasms.
• Verify laterality; if the carcinoma in situ is in the right bronchus or lung, a different code applies.