Case: Testicular oligometastasis from prostate cancer - Report of rare isolated recurrence after radiotherapy and intermittent androgen-deprivation therapy

[Secondary tumors localized in testis]

Testis tumors are uncommon in oncology, and testicular metastasis from distant solid tumors are even rarer. We present two cases encountered in our department of pathology in CHU de Rennes, France. Moreover, we collected all reported cases in the Medline/PubMed databases of non-hematopoietic secondary testis tumors in adults, excluding autopsy studies, to propose an integrative study on this topic. In total, we report 98 cases of secondary testis lesions to prostate (n=38, 38.77 %), colorectal (n=19, 19.39%), gastric (n=12, 12.24%), kidney (n=7, 7.14%), lung (n=6, 6.12%) and other primary cancers. The median age at diagnosis was 66.5 years. We identified significantly more prostate adenocarcinoma (P<0.0001) when the primary tumor was known and significantly more colorectal adenocarcinoma (P=0.035) and pancreatic adenocarcinoma (P=0.002) when the primary tumor was unknown. The age at diagnosis was older when the primary tumor was known (P=0.007). We present the challenges for the diagnosis and propose some elements for diagnosis orientation. Finally, we discuss the possible ways of metastatic dissemination from primary site to testis, as illustrated by the two cases we present.

Isolated Testicular Metastasis Diagnosed More than a Decade and a Half Post Primary Treatment for Prostate Cancer

Prostate cancer is the most common visceral malignancy among men. It rarely metastasizes to the testicles. We herein present the case of a male patient who underwent a radical prostatectomy for a grade group 3 Gleason score 7 (4 + 3) prostate adenocarcinoma followed by adjuvant radiation therapy and continuous androgen deprivation therapy after his first biochemical recurrence. Despite optimal management, prostate-specific antigen (PSA) levels rose back up, upon which a PET/CT ⁶⁸Gallium scan demonstrated an isolated left testicular lesion that turned out to be of prostatic origin following orchiectomy. Testicular metastases from prostate cancer are of unknown prognosis, and the current treatment modality favors an orchiectomy.