多発性骨髄腫の経過中に発生した頭蓋骨の巨大形質細胞腫の1例

Giant Plasmacytoma of the Skull Which Appeared in the Clinical Course of Multiple Myeloma : A Case Report

　症例は51歳女性で9年前から多発性骨髄腫の診断で加療を受けていたが，入院の3カ月前から左側頭部の膨隆が出現した。頭部CT scanでは左中頭蓋窩に境界明瞭な軽度高吸収域の大きなmassがあり，造影剤により増強された。骨のウインドウレベルでは同部位の広範囲な骨融解所見を伴い，それ以外に多発性のpunched out lesionが認められた。頭部MRIではこのmassはT1強調画像で軽度high-intensityを呈しin—fratemporal fossaにも及びGd-DTPAで増強された。左側頭葉は後内側上方へ圧排され菲薄化しmassは側頭部へ膨隆していた。生検を行い形質細胞腫の診断を得てRanimustine 100 mg, Cyclophosphamide 400mgの化学療法および30 Gyのコバルト60の局所照射を行い腫瘍の縮小を認めた。多発性骨髄腫の頭部病変は大抵はpunched out lesionであり，本症例の如く巨大な形質細胞腫を形成することは稀であるので報告する。

A 51-year-old woman with large plasmacytoma occurring from the temporal bone is presented. She has a history of multiple myeloma for 9 years. She manifested marked swelling in the left temporal area with tenderness. Neurological examination revealed no abnormality. She showed monoclonal free light chain (lambda type) in the serum and urine, and had multiple osteolytic lesions in her general bones. T₁ WI of MRI exhibited a huge mass showing slightly high intensity in the left middle fossa and infratemporal fossa, and a part of the mass protruded into the extracranial space. The mass was markedly enhanced by Gd-DTPA. Angio-graphy showed a hypervascular mass supplied by the external carotid artery. Biospy disclosed plas-macytoma. She underwent local irradiation of 30 Gy and chemotherapy of Ranimustine (100 mg) and Cyclophosphamide (400 mg) . The tumor reduced its size, and tenderness in her temporal area disappear-ed.