Identifying lung cancer in patients with active pulmonary tuberculosis

The diagnosis of lung cancer can be delayed in patients with a history of infection with pulmonary tuberculosis that present with new lesions on chest imaging, due to a high initial index of suspicion for mycobacterium tuberculosis complex rather than malignancy. This may lead to diagnosis of malignancy at a more advanced stage of the disease with subsequent increased morbidity and mortality. We reviewed the current literature to evaluate various methods of differentiating between a diagnosis of lung cancer and tuberculosis including radiography, computerized tomography (CT), positron emission tomography (PET) and various biological markers. We included only papers published in English. Based on current data, we recommend that patients established as high risk, according to the American Association of Thoracic Surgery, patients with age greater than or equal to 55 years and a smoking history of greater than or equal to 30 pack years, should be assessed with CT for underlying malignancy prior to beginning tuberculosis treatment, even in the presence of a clinical or microbiologic diagnosis of tuberculosis. In patients with equivocal CT findings, we recommend examination of tumor markers miR128, miR210, miR126 along with CEA, if these tests are at the clinician's disposal.