18F-FDG PET-CT Diagnosis of Tuberculosis in Celiac Lymph Nodes

Abstract

The special location of abdominal tuberculosis makes it difficult for biopsy, while its clinical and imaging characteristics make it indistinguishable from tumors. Here, we report a female patient that was initially misdiagnosed with pancreatic cancer, but eventually correctly diagnosed with tuberculosis in the celiac lymph nodes using ¹⁸F-FDG PET-CT. She was 38 years old. Her main complaint was "deep abdominal pain and discomfort for nearly a month", accompanied by nausea and vomiting. Diagnosis of pancreatic tumors or enlarged lymph nodes was initially made based on CT scan results. Abdominal MRI revealed enlarged lymph nodes. ¹⁸F-FDG PET-CT imaging revealed a soft-tissue mass about 2.8 cm in diameter in the hepatic hilar area with a maximum standardized uptake value (SUV_max) of 9.4, and delayed imaging measured the SUV_max at 12. Enhanced CT showed no vascular envelopment in the mass. Based on these results, the patient was diagnosed with tuberculosis in the celiac lymph nodes. Her tuberculin test was strongly positive. After 5 months of antituberculosis treatment, the mass had reduced to about 1.5 cm in diameter and SUV_max reduced to 8.1, as demonstrated by ¹⁸F-FDG PET-CT imaging. Abdominal lymph-node tuberculosis is easy to misdiagnose, but timely ¹⁸F-FDG PET-CT imaging combined with tuberculin testing may reduce misdiagnosis and mistreatment.

Keywords: 18F-FDG PET/CT imaging; differential diagnosis; lymph-node tuberculosis.

Figure 1

¹⁸F-FDG PET/CT tumor imaging before treatment. (A) CT; (B) PET; (C) PET–CT fusion 1 hour after injection; (D) PET–CT fusion 2 hours after injection; (E) full-body projection shows a fused soft-tissue mass about 2.8 cm in diameter in the hilar area (left front of the inferior vena cava), with punctate high-density shadows, unclear boundaries with surrounding tissue, and abnormal concentration of imaging agent in the mass. SUV_max was 9.4, and delayed display showed SUV_max of 12.0.

Figure 2

Enhanced CT before treatment revealed no vascular envelopment in the mass, but the mass pressing on blood vessels. (A) arterial phase cross section; (B) venous phase cross section; (C) delayed-phase cross section; (D) venous phase coronal section.

Figure 3

Reexamination using CT and ¹⁸F-FDG PET–CT tumor imaging 5 months after antituberculosis treatment. (A) CT; (B) PET–CT fusion 1 hour after injection. The fused soft-tissue mass in the hilar area (left front of the inferior vena cava) became smaller, with a diameter of about 1.5 cm, and the inner dots were high in density. The shadow had increased, and the boundary with surrounding tissue was still unclear. The concentration of imaging agent in the mass was lower, and SUV_max was 8.1.