[Carcinomatous meningitis from prostate cancer diagnosed by cerebrospinal fluid cytology and magnetic resonance image: a case report and review of the literature].

A 55-year-old man was treated with 10 courses of intermittent Paclitaxel, estramustine phosphate sodium and carboplatin (PEC) chemotherapy for hormone-refractory prostate cancer. He was admitted to our department with a complaint of severe headache 2 years after initiating chemotherapy. Enhanced computed tomography (CT) of the brain demonstrated no obvious lesion, but a brain dynamic magnetic resonance image (MRI) showed a diffusely enhanced lesion on the surface of the brain. Cerebrospinal fluid cytology revealed adenocarcinoma cells; and therefore it was diagnosed as carcinomatous meningitis metastasized from prostate cancer. After glycerin and betamethasone were used to control brain edema, the patient's headache temporarily improved. However, he died on the 36th day after admission in the natural course of the disease after he and his family selected not to undertake further active treatment. To our knowledge, only 6 cases of carcinomatous meningitis associated with prostate cancer have been reported in Japan. It is generally difficult to diagnose carcinomatous meningitis because the symptoms vary considerably. Once diagnosed, active treatment is not undertaken in most cases since the patient cannot tolerate further treatment. The prognoses for patients with advanced prostate cancer and metastatic carcinomatous meningitis are generally quite poor. Early diagnosis and prompt initiation of therapy could improve the quality of life for such patients. In this case study, MRI was superior to CT for imaging a metastatic carcinomatous meningitis lesion.