Extrapulmonary tuberculosis (TB) refers to the hematogenous spread of Mycobacterium tuberculosis.
Pathology
Extrapulmonary tuberculosis can occur as a primary form of the disease, i.e. direct infection of an extrapulmonary organ without the presence of primary pulmonary tuberculosis or it can occur as a result of the spread of primary pulmonary tuberculosis.
It appears classically as tuberculous granulomata (tuberculomas) within the affected organs. However, certain forms of the disease exist manifesting with specific findings:
- CNS
- head and neck
- musculoskeletal
-
abdominal tuberculosis
- gastrointestinal tuberculosis
- tuberculous peritonitis
- tubercular lymphadenopathy
- visceral tuberculosis
- hepatic tuberculosis
- gallbladder tuberculosis
- pancreatic tuberculosis
- splenic tuberculosis
-
genitourinary tuberculosis
- renal tuberculosis
- bladder and ureteric tuberculosis
- prostatic tuberculosis
- scrotal tuberculosis (testes, epididymis, seminal vesicles, ductus (vas) deferens)
- tuberculous pelvic inflammatory disease (female)
Radiographic features
Widely variable dependent on the site of involvement. It is best to refer to site-specific articles.
As tuberculous organ infection can mimic malignant disease recent studies have reported the usefulness of 18FDG PET-CT in evaluating and following up patients in whom the diagnosis is in doubt 4.