MRIが診断に有用であった悪性腫瘍の頭蓋内転移例

Magnetic resonance imaging was useful in the diagnosis of leptomeningeal carcinomatosis

　CT検査で異常所見が認められず，MRIで初めて頭蓋内転移を認めた乳癌患者の1症例を経験した。7年前に根治的乳房切除を受けた49歳女性で，最近うっ血乳頭および外転神経麻痺などの脳圧亢進症状を訴え来院した。両眼のうっ血乳頭および外転神経麻痺を認めた。CT検査では異常がなく，MRIのT1強調像で髄膜表面に腫瘍像を確認しえた。悪性腫瘍の頭蓋内転移が疑われた場合，CTだけでなく積極的にMRIを行う必要があると考えられた。

A 49-year-old female was referred to us due to sudden diplopia since 2 months before. She had been diagnosed as breast cancer 7 years before. She underwent surgical removal of the tumor followed by chemotherapy. When first seen by us, she showed bilateral abducens palsy and papilledema. Although the findings were suggestive of intra-cranial metastasis of carcinoma, computed tomo-graphy of the brain gave negative results. Definite diagnosis of leptomeningeal metastasis of the tumor was made based on magnetic resonance imaging (MRI). The present case illustrates the value of MRI in suspected tumor metastasis in the cranial cavity.