Extensive cerebral metastases from neuroendocrine carcinoma of the prostate.

Abstract

Sir, a 78-year-old man was admitted for evaluation of acute confusional state. He had a history of inoperable prostatic carcinoma with orchiectomy 6 years prior to admission and had received chemotherapy with cisplatin for hepatic metastases the year before (results of histological studies were not available). A computed tomography scan did not reveal any relevant pathological findings; notably, no metastases could be seen. Clinically, the man was somnolent and could neither give date, time nor location correctly. There were no pareses or apparent sensory disturbances. Brainstem reflexes were all normal. The plantar response on both sides was flexor. The man’s confusion was attributed to hypovolemia, and the clinical status gradually improved after administration of fluid and electrolytes. After 5 days, the man was released to home. He was admitted again 10 days later, and this time he was stuporous, and both plantar responses were extensor. Despite admission of fluids and electrolytes, the man’s condition rapidly deteriorated, and he died 5 days after the second admission. An autopsy was performed, which disclosed extensive carcinoma of the prostate with capsular penetration and infiltration of surrounding tissues, including the bladder neck (pT4). Haematogenous metastases were found in the liver, the vertebral bones and the pleura. There were signs of former transurethral resection procedures and bilateral orchiectomy. Histological examination of the tumor revealed small cells without glandular differentiation (Fig. 1). Immunohistochemistry demonstrated an expression of pan-cytokeratin, synaptophysin (Fig. 2) and chromogranin A, whereas the reaction against prostate-specific antigen (PSA), prostate-specific acid phosphatase (PSAP), and neuron-specific enolase (NSE) was negative. A diagnosis of small-cell neuroendocrine carcinoma of the prostate was made. The evaluation of the brain revealed innumerable welldemarcated nodules, mostly located at the junction of gray and white matter in cerebrum and cerebellum as well as in the brainstem. Diameters varied from a few millimeters up to about 1 centimeter (Fig. 3). Each of the nodules was surrounded by moderate peritumoral edema, and there were only slight signs of global brain swelling and herniation phenomena. Histological analysis showed solid sheets of atypical epithelial cells that were similar to the prostatic cancer cells with respect to conventional morphology as well as immunohistochemistry. Neuroendocrine (NEC) or small-cell carcinoma of the prostate is fairly uncommon, accounting for less than 1%