A 48 year-old woman was admitted to our hospital with a history of non-radiating pain in the right upper quadrant and epigastrium associated with nausea and bloating (dyspepsia) for the past 20 days. There was no previous history of TB or contact with any TB patient. At the time of admission, on physical examination, except tenderness in the right upper quadrant, no other physical finding was detected. Lab tests: hemoglobin 11g/dl; white blood cells 10000/mm3 (78% neutrophils); platelet count 270,000/mm3; erythrocyte sedimentation rate: 35/mm at the end of the first hour; blood urea 25mg/dl; creatinine level 0.9mg/dl; total bilirubin of 1mg/dl with direct component of 0.4; AST 24U/L; ALT 32U/L (normal range for AST is 17-59U/L and for ALT is 21-72U/L). Routine and microscopic examinations of stool revealed no cyst or ova; blood for amoebic serology was negative. HIV test was negative. Chest x-ray (CXR) was normal. Ultrasonography (US) of the abdomen revealed a hypoechoic lesion measuring 43*35mm in the anterior and sub capsular right lobe of the liver suggestive of an abscess. All other abdominal viscera appeared normal with no free fluid. A computerized tomographic (CT) scan of the abdomen showed sub capsular, well-defined cystic lesions in the right liver lobe (Figure 1).
Then, 20 cc of pus was aspirated under US guidance and sent for microbiological investigations. Routine bacteriological cultures of the aspiration fluid were negative for bacterial infection and fungus. The patient was started on parenteral metronidazole 750 mg/tds and ciprofloxacin 400 mg/bid for 14 days with provisional diagnosis of amoebic or pyogenic liver abscess. Due to poor response to initial treatment, US was repeated and showed persistence of the liver abscess in the anterior and sub capsular right lobe. Repeated aspiration under CT guidance was performed and 10 ml of the cloudy cream-colored pus was sent for Ziehl-Neelsen staining, acid fast bacilli [AFB] culture, polymerase chain reaction (PCR) for TB and other routine microbiological investigations and cytology; which were all negative but the sample was positive on PCR for Mycobacterium tuberculosis and diagnosis of TLA was made. Then, laparoscopy was performed and peritoneal biopsy showed granulomatous peritonitis with caseating necrosis most compatible with TB. The four first line systemic anti TB drugs (isoniazid 300mg/ po, rifampin 600mg/ po, pyrazinamide 1500mg/ po, ethambutol 1000mg/ po) were started. The patient is currently receiving anti TB medications and is asymptomatic. The repeat US of the liver revealed regression of the abscess.