In simple words: This code is used to track cases where a doctor has diagnosed a patient aged 18 or older with the earliest stage of colon cancer, stage 0, where the cancer is only in the lining of the colon.

AJCC colon cancer, Stage 0 documented (ONC). This code is used to document that a patient 18 years of age or older has been diagnosed with stage 0 colon cancer according to the American Joint Committee on Cancer (AJCC) staging system. Stage 0 colon cancer is also known as carcinoma in situ or intramucosal carcinoma, meaning that the abnormal cells are confined to the innermost layer of the colon lining (mucosa).

Example 1: A 45-year-old patient undergoes a colonoscopy during a routine screening. Biopsy results reveal carcinoma in situ, consistent with AJCC stage 0 colon cancer. Code 3382F is reported to track the stage of the cancer., A 60-year-old patient with a history of polyps presents for a surveillance colonoscopy. A small area of abnormal tissue is discovered and biopsied. The pathology report indicates stage 0 colon cancer. Code 3382F is used for performance measurement purposes, documenting the cancer stage., An 80-year-old patient undergoes surgery for what was initially believed to be a benign polyp. However, intraoperative pathology reveals stage 0 colon cancer. Code 3382F is reported to indicate the confirmed stage of the cancer.

Documentation should include the diagnosis of colon cancer, confirmation of AJCC stage 0, and the patient's age (18 years or older). Pathology reports, biopsy results, and clinical notes should support the diagnosis and stage.

** The use of this code may help in tracking quality measures related to colon cancer screening and diagnosis. It allows healthcare providers to collect data on the stage at which colon cancer is diagnosed, which can help assess the effectiveness of screening programs.