Brain metastasis from extramammary Paget's disease of the scrotum

We present to our knowledge the first patient with histopathologically proven brain metastasis from extramammary Paget's disease (EMPD) and discuss the effect of brain radiation therapy for this condition. A 68-year-old man presented to our hospital with headache and gait disturbance. Brain MRI showed multiple enhancing mass lesions, and two large cystic lesions in the left cerebellum. The patient had been diagnosed with scrotal Paget's disease 3 months previously but no further management had been performed due to his refusal. The patient underwent stereotactic aspiration and biopsy of the two large cystic lesions. A histopathological examination revealed that the tumor was a metastatic adenocarcinoma. Immunohistochemical staining revealed that the tumor cells were strongly positive for cytokeratin 7 and moderately positive for carcinoembryonic antigen and gross cystic disease fluid protein 15. These findings were similar to those of his scrotal skin lesions and were consistent with metastatic EMPD. The patient underwent brain radiation therapy with a total radiation dose of 30 Gy in 10 fractions. The patient improved neurologically so as to be self-ambulatory, and a mild improvement in the metastatic tumors was found on follow-up MRI. We had planned systemic chemotherapy, but the patient died of acute respiratory failure 2 months after radiation therapy.