Abdominal Tuberculosis

Dr Manoj K Ghoda M.D., M.R.C.P.

Consultant Gastroenterologistmkghoda@yahoo.com

35/ M

•Recurrent RIF pain•“Gola” formation•Vomiting •Weight loss

USG: ‘Stricture” in terminal ileum, s/o ? Terminal ileal TB

Abdominal TB fact file

•Tuberculosis (TB) is very common in the developing world. Its reappearance has increased in association with the AIDS.

•TB in its various forms remains an important cause of morbidity and mortality in developing countries and in patients with AIDS.

•TB can occur in persons of any age, although it is more common in children and in older persons whose immune systems are weak.

•TB can be seen in any age group that is immunocompromised

•The occurrence of abdominal TB is independent of pulmonary disease in most patients, with an incidence of coexisting disease varying from 5 to 36%.

•In patients with abdominal TB, the highest incidence of disease was noted in the GI tract and in the peritoneum, followed by the mesenteric lymph nodes. •Within the GI tract, the ileocecal area is the most common site of involvement. A third of patients will report a family history of tuberculosis.

The mode of spread:

•The majority of abdominal disease is either through hematogenous spread from active pulmonary or miliary tuberculosis, swallowing of infected sputum or ingestion of contaminated milk or food, and contiguous spread from adjacent organs.

•Associated active pulmonary tuberculosis is only seen in 5-36% of cases.

Pathology:

Three types of intestinal lesion are seen;•Ulcerative, • Stricturous, •Hypertrophic,

though the three may co-exist.

(1) The ulcerative form of TB is seen in approximately 60% of patients. Multiple superficial ulcers largely confined to the epithelial surface. This is considered a highly active form of the disease with the long axis of the ulcers perpendicular to the long axis of the bowel.

(2) The stricturous form shows multiple or single stricture, often very tight.(3) The hypertrophic form is seen in approximately 10% of patients and consists of thickening of bowel wall with scarring, fibrosis, and a rigid, mass-like appearance that mimics carcinoma.

The ulcerohypertrophic form is a subtype seen in 30% of patients. These patients have a combination of features of the ulcerative and hypertrophic forms.

The serosal surface may show nodular masses of tubercles. In some cases, aphthous ulcers may be seen in the colon.

Caseation may not always be seen in the granuloma, especially in the mucosa, but they are almost always seen in the regional lymph nodes.

Clinical presentations of abdominal TB:

•The commonest presentation is non-specific abdominal pain, associated with anorexia, weight loss and low grade fever.

•Systemic manifestations including low grade fever, lethargy, malaise, night sweats, and anorexia and weight loss are present in approximately a third of patients with abdominal tuberculosis.

•Alteration in bowel habit, diarrhea, constipation or together, malabsorption, rectal bleeding etc.

•Ascites.

Complications of abdominal TB:

•Subacute or acute intestinal obstruction due to stricture or adhesions is the commonest complication.•Hemorrhage and perforation are recognized complications of intestinal TB, although free perforation is less frequent than in Crohn’s disease. •Malabsorption may be caused by obstruction that leads to bacterial overgrowth, a variant of stagnant loop syndrome. Involvement of the mesenteric lymphatic system, known as tabes mesenterica, may retard chylomicron removal because of lymphatic obstruction and result in malabsorption. •TB is a well recognized cause of rectal stricture. Isolated rectal involvement is rare and may be mistaken for rectal malignancy

Investigations:

Endoscopy may show,•Ulcers, •Nodules, •Deformed cecum and ileocecal valve, •Strictures, •Multiple fibrous bands, and•Polypoid lesions

Barium examination:

A small-bowel barium study may show dilated loops, thickened folds or even a stricture.

USG:

•Intra-abdominal fluid, free or loculated; clear or complex with septae or debris •Inter loop ascites.•Lymphadenopathy, discrete or conglomerated, •Bowel wall thickening, and •Pseudo kidney sign.

CT : •The CT features suggestive of abdominal TB include, •Irregular soft-tissue densities in the omentum,•Low-attenuating masses surrounded by thick solid rims, •Low-attenuating necrotic nodes, •High-attenuating ascitic fluid and bowel loops forming poorly defined masses. •Splenomegaly and hepatomegaly with nodules, •Pleural effusion, •Intrahepatic, intrasplenic, and intrapancreatic masses.

In clinical practice, typical GI symptoms mentioned above with USG evidence of either terminal ileal involvement or ascites are reasonable evidence in a proper set up.

Further confirmation is by diagnostic ascitic tapping and endoscopic biopsy.

Differential Diagnosis:

•Crohn’s disease,•Gastrointestinal malignancy, •Sarcoma, •Amebiasis, •Yersinia infection, and •Periappendiceal abscess

Treatment:

•Due to the difficulty and in the case of culture the delay associated with making a diagnosis of abdominal tuberculosis, empirical treatment of suspected cases may be warranted.

•Even lesions causing partial bowel obstruction often respond to medical treatment.• •In the HIV co-infected patient as in this case the decision as to whether to start both quadruple therapy and HAART depends on the CD4 count. If CD4 > 200 HAART is deferred until completion of TB treatment, if 100-200 then HAART should start 2 months after initiation of TB treatment and soon after TB treatment if CD4 <100.

Surgery in TB:

Surgery is required if there is a tight fibrotic stricture which is symptomatic. Resection anastomosis or stricturoplasty are the standard approaches. Results are excellent.

Entrance test

The following are true about abdominal tuberculosis:

1. Abdominal tuberculosis (TB) is very common in the developing world but it is rarely seen in western countries.

2. Its reappearance has increased in association with the acquired immunodeficiency syndrome (AIDS).

3. The occurrence of abdominal TB is dependent of pulmonary disease in most patients.

4. In patients with abdominal TB, the highest incidence of disease was noted in the gastrointestinal tract and in the peritoneum, followed by the mesenteric lymph nodes.

5. Within the gastrointestinal tract, the ileocecal area is the most common site of involvement.

6. A third of patients will report a family history of tuberculosis. 7. TB can occur in persons of any age, although it is uncommon in

children and in older persons whose immune systems are weak.

8. The mode of spread is either through hematogenous spread from active pulmonary or miliary tuberculosis, swallowing of infected sputum or ingestion of contaminated milk or food, and contiguous spread from adjacent organs.

9. Most cases of abdominal tuberculosis involve the intestine with the commonest site being the ileocecal region due to abundance of lymphoid tissue (Payer’s patches).

10. Ileocecal junction is involved in 80-90% of the patients. 11. Proximal small intestinal disease is seen more commonly with

Mycobacterium avium-intracellulare (MAI) complex infection, predominantly one involving the jejunum.

12. Three types of intestinal lesion are seen; Ulcerative, Stricturous and hypertrophic.

13. Patients may present with non-specific abdominal pain, with ascites, alteration in bowel habit, diarrhea, constipation or together, malabsorption, rectal bleeding etc.

14. Colonic TB rarely is associated with ileal TB. 15. Subacute or acute intestinal obstruction due to stricture is

the commonest complication.16. Hemorrhage and perforation are recognized

complications of intestinal TB, and free perforation is more frequent than in Crohn’s disease.

17. TB never involve rectum and isolated rectal involvement suggests rectal malignancy.

18. A small-bowel barium study is the main radiographic method for the evaluation of intestinal TB in regions of the world where the disease is endemic.

19. However, because peritonitis is common in GI TB, abdominal CT may be performed as a preferred examination, which nearly always suggest the diagnosis in the presence of necrotic lymph nodes or changes suggestive of TB peritonitis.

20. Early changes on barium examinations reveal nodular thickening of mucosal folds with loss of symmetry in fold pattern.

21. Definitive diagnosis is by showing AFB microbiologically by culture or by both smear and PCR positivity.

22. If the diagnosis of TB is not possible using both of these methods, a clinical diagnosis of TB is ruled out.