Carcinoma of the prostate clinically and radiologically simulating malignant lymphoma.

A 65-year-old man presented with supraclavicular, mediastinal, and retroperitoneal lymphadenopathy clinically thought to be due to malignant lymphoma. Biopsy of a supraclavicular lymph node revealed metastatic adenocarcinoma positive for prostatic-specific antigen. This site of the primary tumor was confirmed by needle biopsy of the prostate gland. The tumor regressed dramatically following treatment with estramustine phosphate.