case_images: PMC7357051_01
case_images: FDG-PET showing increased uptake at site of rectal tumor (top arrow) and presacral lymph node (bottom arrow). While FDG-PET did not pick up any activity in the prostate, it cannot be ruled out that a possible reason for lack of uptake was due to washout from a more intense signal from the rectal lesion as shown in the top arrow.
case_images: 10.1177_2324709620941313-fig1.jpg
case_images: PMC7357051_01_10.1177_2324709620941313-fig1.jpg
case_images: fig1-2324709620941313
case_images: Given the incidental finding of prostatic enlargement and possible sclerotic bone lesion of the left iliac crest appearing quite suspicious, an FDG-PET scan was done and confirmed the primary rectal tumor with a presacral lymph node, but did not reveal any increased uptake in the prostate or iliac crest (Figure 1).
case_images: PSMA-PET showing increased uptake in the prostate (red arrow).
case_images: 10.1177_2324709620941313-fig2.jpg
case_images: PMC7357051_01_10.1177_2324709620941313-fig2.jpg
case_images: fig2-2324709620941313
case_images: PSMA-PET revealed increased uptake in the prostate, which was not previously detected by FDG-PET (Figure 2).
case_images: PSMA-PET showing a lesion in the iliac crest (red arrow), but without uptake (yellow).
case_images: 10.1177_2324709620941313-fig3.jpg
case_images: PMC7357051_01_10.1177_2324709620941313-fig3.jpg
case_images: fig3-2324709620941313
case_images: There was no uptake in the iliac crest (Figure 3).
case_images: Sagittal MRI showing a left iliac bone lesion, which was classified as an intraosseous lipoma by the radiologist due to defined margin and central necrosis.
case_images: 10.1177_2324709620941313-fig4.jpg
case_images: PMC7357051_01_10.1177_2324709620941313-fig4.jpg
case_images: fig4-2324709620941313
case_images: After careful evaluation by the radiologist and nuclear medicine physician, it was determined that given the appearance of the lesion on MRI as calcification with well-defined margins and central necroses and the lack of uptake by PSMA-PET, which is highly sensitive for prostate metastases, the lesion likely represented an intraosseous iliac lipoma instead of a metastasis (Figure 4).