Biochemical Recurrence of Prostate Cancer Presenting as Solitary Testicular Metastasis on 68Ga-Labeled Prostate-Specific Membrane Antigen Ligand Positron Emission Tomography/Computed Tomography

Abstract

Prostate adenocarcinoma (PCa) is the most frequently diagnosed malignancy in the male population, with the most common sites for secondary lesions being the lymph nodes, bones, and lungs. Testicular metastases from PCa are very rare and mostly identified incidentally after therapeutic orchiectomy for advanced PCa or during autopsy. Here we present a case involving a 64-year-old man with biochemical recurrence of castrated oligometastatic PCa that presented as solitary testicular metastasis on Ga-PSMA ligand positron emission tomography/computed tomography.

Testicular metastasis in prostate cancer: A rare case of testicular metastasis diagnosed with 68Ga-PSMA and review of the literature

“…9 Since it is a new technique, the number of cases in which testicular metastasis is detected with 68 Ga-PSMA in prostate cancer is limited. [10][11][12][13][14][15][16] Literature review via PubMed, MEDLINE and Embase database was carried out, and nine published cases published in English were identified between 2017 and August 2021 (Table 1). Of these reports, eight were treated with primary radical prostatectomy, and one with radiotherapy and hormone therapy.…”

Combined DNA repair defects in testicular metastasis from prostate cancer sensitize to immune checkpoint blockade

“…[ 3 ] In rare cases, it may be an incidental finding on high sensitivity imaging, such as 68Ga-prostate-specific membrane antigen positron emission tomography/computed tomography (PET/CT). [ 4 ]…”

“…[3] In rare cases, it may be an incidental finding on high sensitivity imaging, such as 68Gaprostate-specific membrane antigen positron emission tomography/computed tomography (PET/CT). [4] Various mechanisms of metastatic spread of prostate cancer to the testis have been demonstrated in large autopsy studies, including retrograde venous or lymphatic extension, arterial embolism, and spread through the lumen of the vas deferens. [5] Nevertheless, the molecular biology of testicular metastasis from prostate cancer is unknown.…”

“…Detection of testicular metastases is usually guided by local symptoms and may be enabled by use of scrotal ultrasonography, which is the imaging modality of choice [3] . In rare cases, it may be an incidental finding on high sensitivity imaging, such as 68Ga-prostate-specific membrane antigen positron emission tomography/computed tomography (PET/CT) [4] …”

Histologically Confirmed Testicular Metastasis Revealed by [89Zr]Zr-PSMA-617 PET/CT in a Patient with Biochemical Recurrence of Prostate Cancer and Negative Conventional PSMA PET/CT Imaging

“…Of note, the presence of visceral metastases reflects an aggressive tumor biology with unfavorable prognosis [ 9 , 10 ]. Metastases to the testes are a very rare event, although described, and are increasingly diagnosed by PSMA PET/CT [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. When symptomatic or the single site of metastatic spread, surgical resection can be easily performed [ 18 ].…”