急速に進行する両側感音難聴を初発症状とした髄膜癌腫症の1例

A Case of Meningeal Carcinomatosis Initially Presenting as Rapid Progression of Bilateral Sensorineural Hearing Loss

I．はじめに

　髄膜癌腫症とは，悪性腫瘍の癌細胞が脳・脊髄の髄膜へび漫性浸潤することにより髄膜刺激症状，頭蓋内圧亢進症状，脳・脊髄神経障害などを引き起こす極めて予後不良の疾患である^1）。原発部位としては乳癌，肺癌，胃癌などの腺癌あるいは悪性黒色腫が多く報告されている^1,2）。

　今回われわれは，急速に進行する両側感音難聴を初発症状とした乳癌原発の髄膜癌腫症の症例を経験したので報告する。

　Meningeal carcinomatosis is defined as diffuse infiltration of the meninges by metastatic carcinoma. We reported a case of meningeal carcinomatosis,initially presenting as bilateral sensorineural hearing loss. Thereafter the patient presented with rapid progression of deafness,and complete facial palsy. Magnetic resonance imaging（MRI） findings showed that abnormal enhancement of the bilateral inner auditory canals（IACs）. Diagnosis was finally made by cerebrospinal fluid（CSF） cytology which revealed a number of malignant cells that were identical with her previous breast cancer cells. It was considered that the tumor cells have invaded into the bilateral IACs synchronously from CSF,followed by deterioration of bilateral acoustic and facial nerve function.