A 78-Year-Old Man with Weakness and Loss of Appetite for 2 Months

The incidence rate of tuberculosis (TB) in Korea has been consistently decreasing, but the proportion of extrapulmonary tuberculosis (EPTB) remains relatively stable at around 20%. Diagnosing EPTB remains a challenge because clinical samples obtained from relatively inaccessible sites may be paucibacillary, thus reducing the sensitivity of diagnostic tests. Delayed diagnosis and treatment some form of EPTB, such as tuberculous meningitis, can lead to fatal outcomes. Therefore, it is crucial to have a high index of suspicion and perform appropriate testing early on. Obtaining a specimen from the lesion and conducting microbiological tests (acid-fast bacilli smear, mycobacterial culture, and nucleic acid amplification test) along with histopathological examination is essential. When the specimen is limited for all testing, mycobacterial culture test should be prioritized as it has the highest diagnostic yield and allows for drug susceptibility testing. All patients with presumed EPTB should be assessed for pulmonary TB to assess infectiousness and potentially assist with diagnosis.