Interesting image. Utility of FDG metabolism to differentiate synchronous metastatic liver lesions from synchronous colon cancer: nonmucinous versus mucinous adenocarcinoma.

摘要

FDG PET/CT has been increasingly used to evaluate recurrent and metastatic colon cancer. A 73-year-old man with a history of surgical resection for synchronous double colon cancer was evaluated with FDG PET/CT on suspicion of hepatic metastases. In this rare case, we present 2 synchronous metastatic liver tumors with different histologic subtypes (non-mucinous vs. mucinous adenocarcinoma) that showed markedly different FDG-avidity. The dual-time-point scanning technique was performed to aid the detection of lesions. The metastatic mucinous tumor was not seen owing to the relatively lower FDG uptake on the initial scan, but was seen on the delayed scan by increased FDG uptake intensity and the lesion-to-background ratio. Both metastatic tumors showed further increased FDG accumulation on delayed images, but to different extents. We concluded that a distinction in FDG metabolism was useful to differentiate tumors with different histologic types, and the dual-time-point scanning technique could help in the detection of malignant lesions and avoid possible false-negative results.