case_images: PMC11135378_01
case_images: 73-year-old male prostate-specific membrane antigen (PSMA) positron emission tomography-computerized tomography (PET-CT) for biochemical recurrence (a) PSMA PET MIP imaging demonstrates three intensely PSMA expressing nodules (red arrow) within the right hemi-scrotum (on coronal and sagittal projection), as well as a moderately PSMA expressing left common iliac node (blue arrow). (b) Earlier scrotal ultrasound demonstrating a heterogeneously hypoechoic lesion within the right epididymis with associated vascularity, compatible with a metastatic deposit. (c) Axial contrast-enhanced CT: concordant enhancing soft-tissue lesion (yellow arrow) within the right hemi-scrotum, with intense uptake evident on fusion imaging (d). (e and f) Follow-up PSMA PET following anti-androgen therapy shows resolved uptake in the left common iliac node and right epididymis (SUVmax <2.0, less than background) and confirming metastatic foci
case_images: IJNM-39-37-g001.jpg
case_images: PMC11135378_01_IJNM-39-37-g001.jpg
case_images: F1
case_images: A scrotal ultrasound revealed a 16 mm x 14 mm lesion in the right epididymis, initially thought to represent phlegmonous change secondary to epididymitis. 18F-DCFPyL-PSMA PET-CT revealed an intensely PSMA-expressing lesion in the right epididymis (SUVmax 12) and which was new from previous PSMA PET scans, suggesting a prostate cancer metastasis. [Figure 1] No other sites of metastatic disease were demonstrated.
case_images: PMC11135378_02
case_images: 77-year-old male prostate-specific membrane antigen (PSMA) positron emission tomography-computerized tomography (PET-CT) for biochemical recurrence (b) PSMA PET MIP imaging demonstrates a solitary intensely PSMA expressing focus (red arrow, SUVmax 9) within the left hemi-scrotum. Minor increased expression evident in a similar location (in retrospect) on the previous PET from 12 months prior (a). (c and d) Focal region of uptake within the left hemi-scrotum (blue arrow) on axial (c) and coronal (d) projection, with a concordant small enhancing lesion in this location on CT (e). (f) Small hypoechoic lesion within the left epididymis with associated color Doppler vascularity, compatible with a metastasis (yellow arrow)
case_images: IJNM-39-37-g002.jpg
case_images: PMC11135378_02_IJNM-39-37-g002.jpg
case_images: F2
case_images: A 77-year-old male presented with rising PSA level (PSA 1.1 ug/L), 2 years post robotic radical prostatectomy and pelvic salvage EBRT for Gleason 4 + 4 = 8 prostate adenocarcinoma (positive margin and seminal vesical invasion at resection). 18F-DCFPyL-PSMA PET-CT showed a solitary and intensely PSMA-expressing (SUVmax 9) lesion in the left hemiscrotum. [Figure 2] Retrospectively, a faint focus of PSMA expression was seen in the same location on PSMA PET-CT performed 6 months earlier when the PSA level was 0.6 ug/L and initially interpreted as negative for the disease.
case_images: PMC11135378_03
case_images: 62-year-old male restaging prostate-specific membrane antigen (PSMA)-positron emission tomography-computerized tomography (PET-CT) for biochemical recurrence (a) MIP imaging (coronal and sagittal projections) demonstrates bilateral small foci of mild PSMA expression (purple arrows) in the scrotum (SUVmax 3.6). The low level of uptake and bilaterality favors physiological uptake (supported by the absence of any identifiable lesions on a subsequent ultrasound). (b and c) Corresponding areas of mild focal PSMA expression (blue arrows) within the scrotum bilaterally on fusion PET-CT imaging
case_images: IJNM-39-37-g003.jpg
case_images: PMC11135378_03_IJNM-39-37-g003.jpg
case_images: F3
case_images: Mild PSMA expression in the scrotum (SUVmax 3.6) was seen and no disease was present elsewhere. [Figure 3] The low level of uptake and bilaterality, (i.e. symmetric pattern in both epidydmi) favors physiological uptake (also supported by the absence of any identifiable lesions on a subsequent ultrasound).
case_images: PMC11135378_04
case_images: 69-year-old male prostate-specific membrane antigen (PSMA) positron emission tomography-computerized tomography (PET-CT) for prostate cancer staging (a) MIP imaging (coronal and sagittal projections) demonstrates two small foci of mild PSMA expression (purple arrows) in the scrotum bilaterally (SUVmax 4). (b and c) Corresponding areas of mild focal PSMA expression (blue arrows) within the scrotum bilaterally (including within the right epididymis (c) on fusion PET-CT imaging. The low level of uptake is in keeping with physiological PSMA expression (with no focal lesions identified on a subsequent ultrasound)
case_images: IJNM-39-37-g004.jpg
case_images: PMC11135378_04_IJNM-39-37-g004.jpg
case_images: F4
case_images: PMC11135378_05
case_images: 60-year-old male prostate-specific membrane antigen (PSMA) positron emission tomography-computerized tomography (PET-CT) for prostate cancer staging (a) MIP (coronal and sagittal projections) demonstrate a small focus of low-grade tracer uptake (purple arrow) within the right hemi-scrotum, compatible with unilateral physiological PSMA expression. Axial fusion PET-CT shows a corresponding region of mild uptake (blue arrow) localizing to the epididymis on axial (b) and coronal (c) projection. This small focus of PSMA expression was stable on a 12-month follow-up PSMA-PET
case_images: IJNM-39-37-g005.jpg
case_images: PMC11135378_05_IJNM-39-37-g005.jpg
case_images: F5
case_images: A unilateral single small focus of mild PSMA uptake (SUVmax 3.8) was present in the right scrotum/epididymis. [Figure 5] There was no nodal or metastatic disease otherwise present (clinical stage thus N0M0).