Systemic disseminated tuberculosis mimicking malignancy on F-18FDG PET-CT

FDG PET-CT imaging is increasingly accepted as a modality for evaluation of many malignancies, but FDG also can be accumulated intensely by inflammatory lesions. We present a case of a 60-year-old woman with intermittent fever, chills, fatigue, and dyschezia. CT scans indicated colon carcinoma with thoracic and retroperitoneal lymph node metastases. Whole body FDG PET-CT was performed to confirm and stage the malignant disease and showed intense FDG uptake in those lesions. However, histopathology confirmed tuberculosis. The literature describing FDG accumulation in constitutional tuberculous lesions is sparse, and one must be aware of patterns of FDG accumulation in tuberculosis in the diagnosing malignancies.