一過性に画像学的軽快をみたanaplastic astrocytomaの1例

Transient decrease in the size of an enhanced anaplastic : astrocytoma seen on magnetic resonance imaging:a case report

I．はじめに

　脳神経外科領域の疾患で感染，外傷，脳血管障害等は経過上画像学的に軽快を認めることがある．しかしneoplasmのなかでもgliomaの場合には手術，化学療法，放射線療法等の治療なしで画像上軽快を示すことは通常考えにくい．今回steroid theraphyとosmothera—phyのみで造影範囲が一過性に縮小したanaplasticastrocytomaの症例を呈示し，その興味深い病態について考察を加えた．

We report unusual radiographic findings which were seen during the management of a patient with anaplas-tic astrocytoma. An enhanced region in a gyrus of the right frontal lobe was demonstrated in a 38-year-old woman who had had a generalized seizure. Following treatment with steroid- and osmotherapy, this enhanced region decreased clearly on magnetic resonance imag-ing (MRI). Six months later, an enhancing mass lesion appeared in the same position. After surgery, this was diagnosed as being an anaplastic astrocytoma. It is speculated that the initial enhancement was caused by transient dysfunction of the blood-brain barrier follow-ing the seizure. In this case, the most important radiolo-gic image was a T2-weighted image of MRI which was able to demonstrate the existence of the lesion until the time of its removal by surgery.