Abdominal tuberculosis is a rare disease that can be challenging in diagnosis even for a reference hospital. Routine evaluations may be done for tuberculosis but pathognomonic laboratory or radiodiagnostic tests are absent2,4
. In our institute, this patient was the first case of abdominal tuberculosis, causing another difficulty in diagnosis. There were differences in the laboratory findings according to the literature.
In the literature, patients of different ages were reported. The pediatric patients were between 6 months and 16 years old. There were two series for all ages reported from Turkey for abdominal tuberculosis2,4. In these reports, a high percentage was from the pediatric population and median ages were reported as 7 years and 16.2 years.
Our patient had had the BCG vaccination in his history. Progressive primary complex among the BCG vaccinated group has been increasing5. However, the prevalence of abdominal tuberculosis is reported to be almost same over the last 16 years and occurs more in the BCG non-vaccinated children5. Disseminated mycobacterial infection after bacillus Calmette-Guerin (BCG) vaccination is a very rare disorder, and often occurs in patients with immunologic deficiency6. Patients with abdominal tuberculosis may be treated with chemotherapy if they have had the BCG vaccination and if other findings are obviously targeting the disease2.
Erythrocyte sedimentation rate (ESR) can be helpful in evaluating the tuberculosis2. ESR was reported to be high in the literature, but not in our patient. If suspected, ESR may be a guide for the diagnosis, but, as in our patient, it may be within the normal range.
Ultrasonography and computed tomography may be used for the diagnosis2. The most common findings have been reported to be ascites, lymphadenopathy, thickness of the mesenterium and the peritoneum2,3,7. In a study, thickness and fine septation was found to be the most common findings2. USG and CT may be added to the BCG vaccination, ESR elevation, positive tuberculin test and family story to treat the tuberculosis, if biopsy is not possible2.
Peritoneal biopsy with explorative laparotomy or laparoscopy may be indicated2,4,7. If the treatment is planned without biopsy, careful evaluation of the laboratory findings have to be performed2. In biopsy evaluations, mycobacterium tuberculosis may not be detected but granulomatous lesions with caseous necrosis are almost always revealed with the disease. Cytological evaluation of the organism is not always helpful for the microorganisms.
As the culture and AFB positivity of the peritoneal fluid are rarely seen, histological and bacteriologic confirmation may be the only way to make a diagnosis2,3. In a study, it was reported that Mycobacterium tuberculosis DNA was detected by nucleic acid amplification using real-time PCR testing in the peritoneal fluid sample8. For appropriate treatment, PCR is a rapid diagnosis of abdominal tuberculosis9.
Granulomas constitute the characteristic lesions of tuberculosis3. In our case, as the biopsies revealed granulomatous lesions and the clinical progression differentiated some of the other granulomatous lesions like Crohns disease, we started chemotherapy without PCR evaluation.
Chemotherapy is defined as multiple antituberculosis drugs for at least one year of therapy. In a study, isoniasid (10 mg/kg P.O., for one year), rifampicin (20 mg/kg P.O., for one year), pyrazinamide (30 mg/kg P.O., for the first 2 months), and streptomycin ( 20 mg/kg I.M., for the first month was used for treatment4. In another study, ethambutol (20 mg/kg per day) was also used2. We also used prednisolone, 1mg/kg/day for 15 days. The recommended antituberculous treatment of extrapulmonary TB in children includes the use of a three-drug regimen( ısoniazide, rifampin, and pyrazinamide)3,4,10. Also streptomycin can be used in this combination4. Some clinicians administer corticosteroids routinely for the first 2 or 3 months against fibrosis3. Mortality has decreased from 50 to 3% with the introduction of anti-TB drugs1.
We followed-up the patient for a year with the therapy. The patient is healthy and has no symptoms of the disease now. We will continue to evaluate the patient with clinical and radiological examinations. In one of series reported from Turkey, patients were followed-up for 9 months and all of them recovered from the disease. We also followed up our patient for a year and evaluated the progress of the disease.
In our region, this is the first patient reported and there are some clinical and laboratory differences from the other patients reported in the literature. Our patient was admitted to our clinic with abdominal distention and he did not suffer from abdominal pain. Also it was reported that ESR would be high in reported patients but in our patient ESR was within the normal range. We experienced that exploration of the abdomen and peritoneal and mesenteric biopsies were the only ways to help make a diagnosis.