顔面神経麻痺を契機に発見された肺癌側頭骨転移症例

A case of facial nerve palsy caused by temporal bone metastasis from lung cancer

はじめに

　末梢性顔面神経麻痺の原因の多くはBell麻痺とRamsay Hunt症候群であり，腫瘍による顔面神経麻痺は5％程度と少ない^1）。腫瘍性顔面神経麻痺の大部分は耳下腺，中耳，外耳などの隣接臓器に発生する悪性腫瘍の浸潤によるもので，転移性腫瘍による麻痺は稀である。今回われわれは側頭骨転移によって顔面神経麻痺をきたし，これを契機に発見された肺腺癌症例を経験したので若干の文献的考察を含め報告する。

　We herein report a rare case of facial nerve palsy as an initial symptom caused by temporal bone metastasis from lung cancer. A 75-year-old man presented with a 2-week history of right-sided facial nerve palsy. CT and PET-CT examinations showed tumorous lesions in the right upper lobe of the lung and in the right temporal bone. Pathological examination of the biopsy specimens from the lung and mastoid revealed that the lesions were lung adenocarcinoma with temporal bone metastasis. Mutation of the EGF receptor gene was negative. The patient eventually developed brain/meningeal metastases, and died of septic shock 4 months after the first visit.