Gastrointestinal Tuberculosis (TB): A Great Mimicker!

Abstract

Purpose: INTRODUCTION: Gastrointestinal TB is known as the great mimicker because of its diverse presentations. It is the sixth most common extra-pulmonary site of involvement. Its incidence is predicted to rise with increasing cases of HIV infection. CASE: 66 y/o from Gambia with history of diabetes, hypertension and dyslipidemia presented with generalized malaise, epigastric pain and significant unintentional weight loss for 4 weeks. Travel history included frequent visits to Africa. Initial labs showed Hct=27.2 %, WBC=16 k/μl, albumin=2.9 g/dl, total bilirubin=1.3 mg/dl and ESR=78 mm/hr. CA 19.9 U/ml, AFP and CEA levels were normal. Serology for hepatitis B, hepatitis C and blood cultures were negative. Blood smear for parasites was negative. Transthoracic echocardiogram and CXR were unremarkable. She continued to have intermittent fever spikes of 102-103F despite broad spectrum empirical antibiotic therapy. She was diagnosed with AIDS (CD4=10). Abdominal CT revealed enlarged retroperitoneal lymph nodes with a 3.2cm hypodense lesion in the caudate lobe and in the head of pancreas. MRI revealed 3.5 cm enhancing lesion with irregular rim (T1 hypointense and T2 hyperintense) superior to the head of pancreas at the porta hepatis with restricted diffusion; suggestive of an abscess versus exophytic lesion in the caudate lobe. Bile duct appeared normal. Few tiny non-specific splenic lesions were noted. Gallium scan showed a focus of activity inferior and medial to the liver. Patient continued to have fever with worsening leukocytosis, direct hyperbilirubinemia, coagulopathy. Later, she developed oliguric acute renal failure. CT guided drainage of perihepatic abscess was performed. 90 ml purulent aspirate was obtained. Specimen histology showed reactive mesothelial cells. Culture tested positive for Mycobacterium tuberculosis by DNA prob. No fungus, malignant cell or parasite was detected. Subsequent respiratory cultures grew Mycobacterium tuberculosis as well. Anti-tuberculosis therapy was soon interrupted due to marked elevation in transaminases (AST=4122 U/L, ALT=331 U/L). Patient subsequently developed septic shock and finally died on day 20 of hospitalization. DISCUSSION: TB should be considered in the differential diagnosis of intra-abdominal or hepatic lesions, especially in immunocompromised patients. Liver tuberculosis abscess may mimic common hepatic diseases including primary or metastatic liver cancer, amebic or pyogenic liver abscess. A greater awareness, coupled with high index of suspicion is required to avoid unnecessary delay in diagnosis and treatment of this rare clinical entity; particularly in patients with recent travel history or native to TB endemic areas.