Adenocarcinoma of the prostate presenting initially as an intracerebral tumor

Background. The authors report a patient who was admitted to the hospital with neurologic symptoms and signs that were thought to be caused by a primary intra‐cranial tumor. Methods. Craniotomy resulted in successful resection of an occipital lobe tumor reported histologically as a papillary adenocarcinoma, probably metastatic from the kidney. However, a complete diagnostic study failed to demonstrate the primary focus. Results and Conclusions. Thirteen months later, the patient was readmitted to the hospital and found to have metastatic prostatic carcinoma. Immunoperoxidase staining for prostatic acid phosphatase of the prostatic tissue and of the previously resected brain tumor tissue indicated that the brain lesion was metastatic from the prostate.