Unusual case of emphysematous cystitis seen on FDG PET/CT.

Emphysematous cystitis is a rare condition requiring immediate aggressive medical attention. Here, we describe a very unusual case of emphysematous cystitis seen on FDG PET/CT. This finding was discovered in an 84-year-old man undergoing FDG PET/CT to monitor a known diagnosis of IgG4-related nodular sclerosis. Images revealed gas within the bladder wall and an anterior gas-filled bladder diverticulum. The patient subsequently developed sepsis with cultures revealing Escherichia coli. This case highlights the importance of recognizing this finding on varied imaging modalities, as life-threatening complications may arise from this condition.