鞍上部原発Malignant Rhabdoid Tumorの1成人例

Suprasellar Primary Malignant Rhabdoid Tumor in an Adult : a case report

I．はじめに

　Malignant rhabdoid tumor（以下MRT）は小児の腎に好発する極めて悪性度の高い腫瘍である．中枢神経系原発のMRTはこれまでに80例の報告があるが，小児例が多く成人例は極めて稀である．今回われわれは急速な視力障害を呈した鞍上部原発のMRTの成人例を経験したので，文献的考察を加えて報告する．

Malignant rhabdoid tumor (MRT), described for the first time in 1978 in the kidney, has rarely been re-ported in other organs including the brain and has involved adults in only 3 cases.

We described a case of MET in a 32-year-old woman who presented with severe headache, nausea and sudden onset of visual disturbance. MRI showed a well-enhanced mass at the suprasellar region. Subtotal removal of the tumor was performed. However, tumor regrowth occurred after the operation (doubling time, 8.36 days) and spinal dissemination was detected. Therefore, chemotherapy and radiotherapy were administered focusing on the suprasellar lesion and the spinal cord.

Pathologically, light micrographs showed rhabdoid cells with large, round, single or double nuclei with one prominent nucleolus and eosinophilic cytoplasmic inclusions. Electron micrographs were made of typic-al rhabdoid cells displaying bundles of intermediate filaments within the perikaryon. In immunohistoche-mical studies, EMA, vimentin, cytokeratin and SMA were positive. Pathological findings were consistent with those of MRT.

Optimal treatment for this tumor has not been established. Our case may be useful in defining treatment for MET.