Initial Misdiagnosis of Lung Cancer due to Elevated Carcinoembryonic Antigen in a Patient with Tuberculosis

Background Tuberculosis often presents on imaging in the form of a solitary nodule, sometimes accompanied by elevated CEA, which is clinically difficult to differentiate from lung cancer and prone to misdiagnosis. Methods Lung tissue taken by lung biopsy and sent for NGS and Xpert MTB/RIF finally led to the definitive diag-nosis of nodular foci in the upper lobe of the left lung caused by tuberculosis. Results Enhanced CT of the chest showed nodular foci in the upper lobe of the left lung. Initially the nodules were thought to be malignant, but after a series of tests, were finally confirmed to be tuberculosis. Conclusions In patients with lung disease, when chest imaging reveals a space-occupying lesion accompanied by an elevated CEA level, a comprehensive analysis of the type of lung disease, the patient's age, and comorbidities should be performed before final diagnosis to avoid misdiagnosis and delay in appropriate treatment.