Imaging of extrapulmonary tuberculosis

Diagnosis of extrapulmonary tuberculosis is often difficult. Although posit ive 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 extr apulmonary tuberculosis can help in diagnosis. The spine is the most common site of skeletal involvement. The femur, tibia, and small bones of the han ds and feet are most commonly involved by tuberculous osteomyelitis. Tuberc ulosis of the joints is characteristically monoarticular; the knee and hip are most frequently affected. Central nervous system tuberculosis takes var ious forms, including meningitis, tuberculoma, abscess, cerebritis, and mil iary tuberculosis. Ileocecal involvement is seen in 80%-90% of patients wit h abdominal tuberculosis. The most common manifestation of abdominal tuberc ulosis is lymphadenopathy. Genitourinary tuberculosis is the most common ma nifestation of extrapulmonary tuberculosis. Lymphatic tuberculosis is more common among children, with cervical or supraclavicular nodes most frequent ly involved. Tuberculosis of the breast is extremely rare and occurs most o ften in young, multiparous, lactating women. The radiologic features of ext rapulmonary tuberculosis mimic those of many diseases. A high level of susp icion is required, especially in high-risk populations. A positive culture or histologic analysis of biopsy specimens is still required in many patien ts for definitive diagnosis.