頭蓋骨に発生したMassive Osteolysis—症例報告と文献的考察

Massive Osteolysis of the Skull : Case Report and Review of the Literature

　Massive osteolysisは原因不明の骨融解性病変で，頭蓋骨に発生することは極めて稀である。今回，我々は頭蓋骨に発生したInassive osteolysisと考えられる症例を経験したので，若干の文献的考察を加えて報告する。患者は11歳女性で，6歳頃より徐々に増大する右頭頂骨の無痛性の陥没を主訴にて来院した。頭蓋単純写では，右頭頂骨に辺縁が不正で骨硬化像を伴わない骨透亮像を認めた。CTスキャンでは，外板を中心に一部板間層におよぶ骨欠損が認められた。^99mTC SCintigramでは，頭蓋骨を含む全骨格系に異常集積像を認めなかった。また，種々の血液検査や各腫瘍マーカーは全て正常範囲用であった。頭蓋骨の骨融解性病変で，長い臨床経過を有し，局所的に腫瘍や炎症性所見を欠き，全身的にも特に異常所見を認めない場合は，本症例のようなmassive osteolysisを念頭にいれなければならない。

The authors describe a rare case of massive osteolysis of the skull, along with a brief review of the literature. A 11 year-old female was admitted with a complaint of a painless depression in the right parietal region, which had been slowly enlarg-ing for several years. Skull x-ray films revealed a radiolucent area with irregular and non-sclerotic margin in the right parietal bone. Plain CT showed an osteoytic lesion involving the outer table and diploe with absence of new bone formation. On ^99mTc scintigrams, there were no abnormal accumulation in the whole skeletal system including the skull. Blood examinations including serum calcium, phos-phate, and alkaline phoshatase were entirely nor-mal. In the differential diagnosis of lytic skull lesion, the long, inactive course without any corrob-orative local or systemic evidence of illness, and the absence of new bone formation on radiological examinations clinch the diagnosis of massive osteolysis.