Extrapulmonary forms of tuberculosis

Extrapulmonary tuberculosis is understood as the localization of the pathological process outside the chest cavity; most often this form has a hematogenous route of transmission. There is not a single organ in the human body that could not be affected by tuberculosis; however, some are involved in the pathological process more frequently, while others are affected less often. In the Russian Federation, the most common form of extrapulmonary tuberculosis is tuberculosis of the lymph nodes, the second most common is tuberculosis of the genitourinary system, and the third most common is bone and joint tuberculosis. In different countries, the proportion of patients with extrapulmonary forms of tuberculosis varies from 4 to 16%. Due to the difficulty of diagnosis, about a third of cases of extrapulmonary tuberculosis remain undetected. It is interesting that while pulmonary forms of tuberculosis are found mainly in men, extrapulmonary tuberculosis more often affects women (in 59-63% of cases). This trend is especially clear in tuberculosis of the genitourinary system: 75% of cases are female patients. However, bone and joint tuberculosis has not a gender-specific, but an age-specific prevalence feature: most often it is diagnosed in children aged 0 to 4 years. According to the clinical classification used at the present stage, extrapulmonary forms are a section of “tuberculosis of other organs and systems”.