Penile metastasis from adenocarcinoma of the prostate in a patient with colorectal carcinoma.

Skin metastasis secondary to cancer of the prostate is rare and the prognosis is poor. A 65-year-old male patient diagnosed with metastatic colon carcinoma presented with polyuria and subcutaneous nodular mass on dorsal side of the corpus penis. The serum prostate specific antigen (PSA) level was 111.1 ng/mL and therefore the patient underwent transperineal prostate biopsy. Pathology reported adenocarcinoma of the prostate. The subcutaneous nodular lesion on the penis was totally excised and removed. Immunohistochemical examination of the excised mass was carcinoembryonic antigen (CEA) negative and PSA positive. Taking all these findings into consideration, the patient was diagnosed with prostate cancer that had metastasized to the penis. FOLFOX-4 chemotherapy regime in addition to bicalutamide and goserelin acetate was administered to the patient who also had metastatic colon cancer.