Metastatic tumors to the testicles.

Metastatic tumors to the testicles are rare. The most common primary sites are the prostate, the lung, the kidney, the gastrointestinal tract and the skin (melanomas). The majority of these tumors are diagnosed at autopsy or at orchiectomy for metastatic prostatic carcinoma. Their clinical manifestations can antedate the clinical discovery of the primary tumor and the correct pathologic diagnosis of the testicular tissue may result in the identification of an "occult" carcinoma. Although they commonly occur in old patients with a peak incidence in the fifth and sixth decade, they may also involve younger patients and should be differentiated from primary testicular tumors. The most common routes of metastasis to the testes are the lymphatics, the vas deferens, the spermatic veins and the hematogeneous (arterial) pathways. Their diagnosis, although suspected by the patient's age and clinical symptoms should be confirmed histologically. Their treatment which includes a high inguinal orchiectomy is directed to the primary neoplasm. The prognosis depends on the site, type, grade and extent of the original tumors.