Tuberculous peritonitis is a result of peritoneal involvement with tuberculosis. It is frequently seen in association with other forms of gastrointestinal tuberculosis 6.
Tuberculosis is usually confined to the respiratory system, but may involve any organ system, particularly in those who are immunocompromised 1.
The abdomen is the most common site of extra-pulmonary tuberculosis, with peritoneal disease being the commonest form within the abdomen. Abdominal tuberculosis can also involve the solid organs, gastrointestinal tract, mesentery and lymph nodes 2.
Peritoneal involvement is usually due to direct haematogenous spread, although rarely it can occur following rupture of a tuberculous intra-abdominal lymph node.
Tuberculous peritonitis is divided into three types:
- wet type (commonest): ~90% 1
- dry type
- fibrotic-fixed type
Considerable overlap of the three types can be observed.
Tuberculosis in different organ systems may mimic alternate pathology so histopathological or laboratory evidence is often needed to support suspicions on imaging, before treatment is commenced.
CT imaging features seen with tuberculous peritonitis include:
- nodular or symmetrical thickening of the peritoneum and mesentery
- abnormal peritoneal or mesenteric enhancement
- enlarged lymph nodes of low attenuation - low attenuating lymphadenopathy
In additional there can be more specific imaging features seen with individual types:
- wet type: exudative high attenuation ascites (HU 20-45), which may be free or loculated; high attenuation of the ascites is thought to be due to high protein and cellular content
- dry type: caseous mesenteric lymphadenopathy and fibrous adhesions; thickened, ‘cake-like’ omentum.
- fibrotic type: omental ‘cake-like’ mass with fixed bowel loops; matted loops and mesentery with loculated ascites
The omental involvement may be ‘cake-like’, nodular of smudged, but all appear similar to peritoneal carcinomatosis, which is the main differential diagnosis.
When the gastrointestinal tract is involved mural thickening of the ileo-caecal region is the most common site and can occur in conjunction with peritoneal involvement 4.
On imaging (particulary CT) key differential considerations include:
Other less likely considerations include:
- causative agent
- tuberculoma (tuberculous granuloma)
- tuberculous abscess
- miliary tuberculosis
- pulmonary tuberculosis
- cardiac tuberculosis
- intracranial tuberculosis
- tuberculous otomastoiditis
- gastrointestinal tuberculosis
- genitourinary tuberculosis
- skeletal tuberculosis
- tuberculous mastitis
- tuberculous lymphadenopathy
- tuberculous adrenalitis
- 1. Burrill J, Williams CJ, Bain G et-al. Tuberculosis: a radiologic review. Radiographics. 27 (5): 1255-73. doi:10.1148/rg.275065176 - Pubmed citation
- 2. Suri S, Gupta S, Suri R. Computed tomography in abdominal tuberculosis. Br J Radiol. 1999;72 (853): 92-8. Br J Radiol (citation) - Pubmed citation
- 3. Federle MP, Jeffrey RB, Woodward PJ et-al. Diagnostic imaging, Abdomen. (2009) ISBN:1931884714. Read it at Google Books - Find it at Amazon
- 4. Dähnert W. Radiology Review Manual. (2011) ISBN:1609139437. Read it at Google Books - Find it at Amazon
- 5. Gulati MS, Sarma D, Paul SB. CT appearances in abdominal tuberculosis. A pictorial essay. Clin Imaging. 23 (1): 51-9. Clin Imaging (link) - Pubmed citation
- 6. Engin G, Acunaş B, Acunaş G et-al. Imaging of extrapulmonary tuberculosis. Radiographics. 20 (2): 471-88. Radiographics (citation) - Pubmed citation