Abdominal Tuberculosis Mimicking Cancer Clinically and on Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET) Imaging: A Two-Case Series.

BACKGROUND Miliary tuberculosis (MT) is the disseminated form of tuberculosis (TB) and it is a potentially fatal condition. Diagnosis is often delayed because symptoms are typically nonspecific or absent, and misdiagnosis in favor of other diseases is common. We report 2 cases of disseminated TB that were diagnosed during or after surgeries performed for other suspected diseases. CASE REPORT Imaging findings are not specific and cannot be relied upon to raise suspicion of MT. In the first case, besides other imaging techniques, we also performed a positron emission tomography-computed tomography (PET-CT) on the patient and the resulting, thick, fluorodeoxyglucose (FDG)-avid ring surrounding the liver first led to concern for peritoneal carcinomatosis. TB peritonitis was only identified on laparoscopy and biopsy. In the second case, CT and magnetic resonance imaging (MRI) findings of a solitary liver mass with an irregular enhancing rim and progressive enhancement led to a radiographic diagnosis of likely intrahepatic cholangiocarcinoma, The subsequent finding that the lesion was intensely FDG-avid without other foci of FDG uptake led to the decision to proceed with resection without a prior biopsy. CONCLUSIONS We have presented 2 patients with TB in whom clinical and imaging findings, and in particular, FDG-PET imaging, led to an erroneous clinical diagnosis of malignancy. An awareness that TB remains very much an active clinical problem in North America and that there are other reasons for FDG uptake on PET imaging besides cancer, is necessary in order to avoid unnecessary and potentially deleterious interventions in patients with TB.