多発性頭皮下腫瘤を形成した多発性骨髄腫の1例

Multiple Myeloma Presenting with Multiple Subcutaneous Masses

　要旨　多発性骨髄腫が頭蓋骨病変で発症することは少なく，腫瘤を形成し，腫瘍が硬膜下まで伸展することは少なく，さらに，多発性病変を呈することはきわめて稀である。今回，頭蓋外から病変を透視する再合成画像（Perspective 3D-CT）は術前検討において有用であり報告に加えた。症例は92歳女性。多発性頭皮下腫瘤が増大傾向であったため紹介された。多発性に頭皮下の軟性腫瘤病変を認め，画像上，腫瘍は頭蓋骨の破損部を跨ぎ頭皮下から硬膜外，一部硬膜下に伸展していた。軽度の貧血とIgA型M蛋白が検出されたため，多発性骨髄腫を考え部分摘出術を行った。病理診断上，多発性骨髄腫と確定診断したが，高齢のためquality of lifeを中心に経過を追っている。

　A 92-year-old female was admitted to our hospital with 2-months history of rapidly enlarging subcutaneous masses in the multiple skull's regions. Neurological examination in the admission showed slightly right hemiparesis. Skull X-P showed multiple osteolytic lesions, and CT showed high density masses. MRI revealed iso-intensity masses on both T1 and T2-weighted images. Gd-DTPA enhanced T1-weighted image showed masses with marked homogeneous enhancement like the dural tail sign in the dura adjacent to the tumors. The tumor in the right frontal subcutaneous region was partialy removed ; this mass was diagnosed as multiple myeloma. Because the prognosis of such a case was very poor and she was older, we thought her quality of life（QOL） and she was conservatively treated.

　A case of multiple myeloma having plasmacytoma in multiple skull's regions was reported. Although 30 cases in the literature of multiple myeloma forming cranial or intracranial plasmacytoma were briefly reviewed, multiple lesion was not reported and we thought it as a very rare case. And if such a case was performed to remove all masses, we believed that three dimensional computed tomography images to distinguish the tumors from skull and skin（Perspective 3D-CT; SIEMES's Somatom Emotion 6 ＆ Syngo） was very valuable for the preoperative evaluation of a surgical approach.

（Received : July 14, 2004）