肝細胞癌から慢性硬膜下血腫被膜への転移を生じた1例

Metastasis of Hepatocellular Carcinoma to the Membrane of Chronic Subdural Hematomas:A Case Report

Ⅰ．はじめに

　転移性脳腫瘍は前頭葉，小脳半球，頭頂葉，後頭葉などの脳実質に多く発生するが⁴⁾，硬膜転移を来すものも約10%存在する⁸⁾．硬膜転移は慢性硬膜下血腫を生じる原因となるが¹⁶⁾，外傷により生じた慢性硬膜下血腫の被膜に転移を来した報告例は存在しない．今回われわれは，肝細胞癌治療中に生じた外傷性慢性硬膜下血腫に対して穿頭洗浄術を行った4カ月後に，慢性硬膜下血腫の被膜に肝細胞癌の転移を確認した1例を経験した．稀な病態と考えられたため，若干の文献的考察を含めて報告する．

　An 81-year-old man presented with gait disturbance. Two months previously, he suffered from hepatocellular carcinoma and transarterial chemoembolization was performed. A head computed tomography（CT）scan revealed bilateral chronic subdural hematomas. The patient's gait disturbance was improved after achievement of bilateral burr hole drainage. A head CT two months after treatment revealed no recurrence of the hematomas. However, head CT images obtained four months after treatment revealed an abnormal mass in the right parietal region attached to the internal surface of the skull. The mass was located in the same region from where the chronic subdural hematomas were previously removed via burr hole drainage, and was suspected to have originated from the dura mater. We performed craniotomy and total removal of the mass. The dura mater was intact, and macroscopically, the mass originated from the organized membrane of the chronic subdural hematoma. A pathological examination revealed metastasis of hepatocellular carcinoma to the membrane of the chronic subdural hematomas. Head magnetic resonance imaging（MRI）performed 39 days after craniotomy presented a new lesion in the left parietal region attached to the internal surface of the skull. The patient subsequently died 46 days post-operation. When examining chronic subdural hematomas in cancer patients, histological examination of the dura mater, hematoma, and membrane of the hematoma are important. The possibility of metastasis to the capsule of the hematoma should be considered.