Metastatic Tumors in Testis : Primary Sites
Testicular Metastases - Primary Sites: Virtually any cancer can spread to the testis. Some of the most common primary sites (in decreasing order of frequency; not a complete list) are: ADULTS - prostate, gastrointestinal tract (esp. stomach and colon), kidney, lung, melanoma, urinary tract, pancreas, well-differentiated neuroendocrine tumor (carcinoid), merkel cell carcinoma, and hepatocellular/cholangiocarcinoma. PEDIATRIC (<18 yrs.) - neuroblastoma, Wilms tumor, rhabdomyosarcoma, retinoblastoma, and medulloblastoma. In addition, hematopoietic neoplasms (leukemias and lymphomas) commonly involve the testis, especially in pediatric patients. Testicular Metastases in Prostate Cancer: Testis is an uncommon visceral site for metastases from prostate cancer. However, prostate cancer is over-represented in testicular metastases due to selection bias. Before the availability of chemotherapeutic agents (e.g. LHRH-agonists) to induce androgen deprivation, patients with metastatic prostate cancer often underwent bilateral orchiectomy to remove the source of endogenous androgens. Routine examination of such specimens resulted in frequent detection of testicular metastases even though it is a rare occurrence. The image shows metastatic prostatic adenocarcinoma in a testis. A couple of atrophic seminiferous tubules are also seen.