Background
Lung adenocarcinoma (LA) is the most frequent histological subtype of lung cancer worldwide. This condition is categorized from preinvasive lesions to metastatic adenocarcinoma (1, 2). Smoking is the most common responsible risk factor for LA so far along with a family history of lung cancer, occupational exposure, and genetic mutations. In the early stages, LA can be asymptomatic while in late stages, non-specific symptoms such as coughing, weight loss, and hemoptysis can occur (3).
Miliary tuberculosis (TB) is the wide-spreading dissemination of Mycobacterium tuberculosis through the bloodstream. It can affect single or several organs and through a hematogenous way to the brain (4). Miliary TB can present with non-specific manifestations including fever, weight loss, sweats, and anorexia mimicking other diseases especially primary and secondary lung cancers. Immune suppression due to cancer, HIV infection, malnutrition, diabetes, transplantation, and end-stage renal disease are risk factors for this condition (5).
The miliary pattern in lung imaging can present in miliary TB, occupational lung diseases, different fungal infections, sarcoidosis, and metastatic diseases from primary or secondary lung cancers; therefore, diagnosis cannot be distinguished by CT imaging alone. Further investigations such as serological and pathological tests are necessary for diagnosis (6, 7).
In the current article, we are presenting a young man with no prior medical history or risk factor with metastatic lung adenocarcinoma mimicking miliary TB in imaging.