Metastasis of Prostate Adenocarcinoma to the Testis

Testicular metastasis of prostate adenocarcinoma: the other side of orchiepididymitis

Background

Metastatic prostate adenocarcinoma is a rare event and there are few references to this topic. We report an unusual case of prostate cancer metastasis and review of contemporary literature. Moreover, we discuss the pathogenesis and the clinical aspects of this event.

Case presentation

A 70-year-old patient was admitted to the hospital for right scrotal pain. The ultrasound examination described an increase in testicular size, suggesting the possibility of orchiepididymitis. Past medical history reported a previous prostate adenocarcinoma. Inflammatory blood tests were normal. Importantly, PSA was 3.3 ng/ml. PET scan positivity in the scrotum raised suspicion of a relapse. Therefore, he underwent right orchiectomy.

Conclusion

Although metastatic prostate adenocarcinoma is rare, a correct diagnosis is of paramount importance because the therapy changes accordingly. Patients who complain of scrotal pain need to be examined accurately. Although the most common cause behind this symptom is infectious, the patient's past medical history should be reviewed to exclude previous malignancies.

[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.

The protective effect of metformin against testicular damage in diabetes and prostate cancer model

Individuals with diabetes have an increased risk of breast, colorectal, pancreatic and prostate cancer. Metformin, an oral biguanide used to treat diabetes, has anti-hyperglycaemic, anti-hyperinsulinemic and antioxidant activities. The effects of metformin on testicular tissue damage in cancer and diabetic + cancer rat models were evaluated histologically, immunohistochemically and biochemically. The diabetic model was produced in Copenhagen rats using a single dose of streptozotocin (65 mg/kg), while prostate cancer was induced through subcutaneous inoculation of 2 × 10⁴ Mat-LyLu cells into the animals. At the end of the experimental period, testicular tissues with a close functional relationship to the prostate were collected. Histological evaluation found moderate to severe damage to testes following the diabetes and cancer process. Histopathological and biochemical impairments were observed in the early stage of prostate cancer, which were increased in the diabetic animals. Metformin administration reversed these injuries and provided substantial protection of the testes. In particular, metformin had protective effects on tissue damage, apoptosis, oxidative stress and antioxidant capacity. This suggests that metformin should be further investigated as a targeted protective drug against prostate cancer-related damage to the testes.

Prostate cancer metastasis to the testis: an unexpected presentation of a solitary recurrence

A 74-year-old man with a history of prostate cancer was referred to the urology team with a new left sided testicular lump. He had a background of prostate cancer 4 years previous which had been treated with external beam radiotherapy and androgen deprivation therapy, both of which had been completed. Concurrently, he also had evidence of biochemical recurrence of prostate cancer with a rising prostate-specific antigen (PSA). He underwent a left radical orchidectomy. Following histopathological analysis, this was found to be metastatic spread from his prostate cancer. Subsequent staging showed no evidence of metastatic spread elsewhere. The patient made a good recovery following surgery and his PSA levels returned to undetectable levels. He received no further treatment for metastatic prostate cancer.