転移性脳腫瘍出血で発症した睾丸卵黄嚢腫

Brain Metastasis of Testicular Yolk Sac Tumor with Massive Hemorrhage: Case report

I，はじめに

　睾丸のgerm cell tumorが頭蓋内に転移することは珍しく，全転移性脳腫瘍中0.7％を占めるに過ぎない^25）．中でも非常に稀な睾丸卵黄嚢腫（yolk sac tumor）が頭蓋内転移による脳内出血で発症した症例を経験したので報告し，文献的考察を述べたい．

　A rare case of yolk sac tumor of the testis which metastasized to the brain parenchyma with repeated intra-tumoral hemorrhage is reported. The patient was a 38 year-old-man admitted to the Department of Urology with the chief complaint of painless swelling of the left testis for a period of one year. He underwent orchiectomy with highly suspected malignancy, because chest X-ray examination demonstrated metastatic coin lesions. Pathological examination of the operated specimen showed typical yolk sac tumor of the testis. Postoperative clinical course was uneventful. However, on the 4th postoperative day, the patient suddenly fell into a coma with left hemiplegia and dilated right pupil. CT scan demonstrated an intra-parenchymal hematoma in the right parietal lobe. Emergency craniotomy with evacuation of the hematoma clot was performed. Histological examination of the hematoma clot showed the same histology (yolk sac tumor) as found in the operative specimens of the left testis. After regaining full consciousness, chemotherapy (PEB and PVB) was started. It was effective to reduce the high serum AFP level and the size of the metastatic coin lesions in the lung, However, it was not effective in preventing brain metastasis. He again relapsed into coma due to a newly-developed intra-tumoral hematoma with multiple brain metastasis and died 6 months after the orchiectomy.

　Yolk sac tumor of the testis is rare in adult Japanese and there is no previous report of its metastasis to the brain parenchyma with intratumoral hemorrhage.

　We have reviewed the previously reported cases and discussed the brain metastasis of this malignant urogenic tumor.