Imaging of extrapulmonary tuberculosis

Diagnosis of extrapulmonary tuberculosis is often difficult. Although positive chest radiographic findings or a positive tuberculin skin test supports the diagnosis, negative results do not exclude extrapulmonary tuberculosis. However, recognition and understanding of the radiologic findings of extrapulmonary tuberculosis can help in diagnosis. The spine is the most common site of skeletal involvement. The femur, tibia, and small bones of the hands and feet are most commonly involved by tuberculous osteomyelitis. Tuberculosis of the joints is characteristically monoarticular; the knee and hip are most frequently affected. Central nervous system tuberculosis takes various forms, including meningitis, tuberculoma, abscess, cerebritis, and miliary tuberculosis. Ileocecal involvement is seen in 80%-90% of patients with abdominal tuberculosis. The most common manifestation of abdominal tuberculosis is lymphadenopathy. Genitourinary tuberculosis is the most common manifestation of extrapulmonary tuberculosis. Lymphatic tuberculosis is more common among children, with cervical or supraclavicular nodes most frequently involved. Tuberculosis of the breast is extremely rare and occurs most often in young, multiparous, lactating women. The radiologic features of extrapulmonary tuberculosis mimic those of many diseases. A high level of suspicion is required, especially in high-risk populations. A positive culture or histologic analysis of biopsy specimens is still required in many patients for definitive diagnosis.