Increased splenic fluorodeoxyglucose uptake in a patient with granulomatous angitis

Area of Science:

• Nuclear medicine
• Immunology
• Pathology

Background:

• 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is established for diagnosing large vessel vasculitides.
• The utility of FDG-PET in small vessel vasculitides remains largely uncharacterized.

Observation:

• A 64-year-old female presented with prolonged fever and splenomegaly.
• FDG-PET imaging revealed increased tracer uptake in the spleen.
• Splenectomy confirmed granulomatous angitis, characterized by microaneurysms and inflammation.

Findings:

• The patient's condition was associated with positive myeloperoxidase-antineutrophil cytoplasmic antibody.
• Histopathology confirmed granulomatous angitis, a small vessel vasculitis.
• The spleen, a site of small vessel vasculitis, demonstrated significant FDG uptake.

Implications:

• This case suggests that small vessel vasculitides can exhibit increased FDG uptake on PET scans.
• FDG-PET may be a valuable diagnostic tool for evaluating small vessel vasculitides.
• Findings expand the known applications of FDG-PET in inflammatory vascular diseases.