Glomus Jugulare Tumor—レ線単純撮影による診断

Glomus Jugulare Tumor:Special Reference to the Radiogram of the Jugular Foramen

I．緒言

　Glomus jugulareから発生した腫瘍についてRosen—wasser^16）が最初に記載して以来，多くの報告があるが，わが国では報告された症例は比較的少ない^{7）8）10）11）12）17）18）}。

　Glomus jugulare^6）は頸静脈球の周囲の結合組織の中にある碗豆大のnonchromaffin paragangiionである。それゆえglomus juglare tumorはnonchromaffin para—ganglioma, chemodectomaあるいはreceptomaとも呼ばれる。頸静脈球は頸静脈窩の中にあるため，glomus jugulare tumorの場合，最初にこの部の破壊が起こる。頸静脈窩は鼓室の下壁を形成しているため，腫瘍が発育してこの部を破壊すると容易に鼓室へ侵入し，さらには内耳および外耳道へ拡がる。内耳へ及ぶと難聴，めまい，耳鳴りなどの症状をきたし，外耳道へ拡がると血管に富むpolyp様の腫瘍として肉眼的に認められるようになる。他方頸静脈孔が破壊されるために第9,10,11脳神経の脱落症状（Vernetの症候）を起こしやすい。また後頭骨の外側部および底部の方向へ進展すると舌下神経管に及び舌下神経を侵す。以上のような過程によつて頸静脈孔の境界不明瞭な拡人をきたすにいたる。

It is difficult to demonstrate a canal as jugular foramen that is oblique to various planes, those being utilized as an orientation by routine x-ray examina-tions of the skull. It must give an accurate image on film only by means of the special projection. The jugular foramen is not straight in its own direction, moreover it has rather complicated structures covered by a curved cortex, as fossa jugularis

A number of projections of the jugular foramen which have been remarked in the literature are com-pared to each other with respect to easiness in pro-jection technique, exactness in depicting the outline of the foramen and clearness in its contrast. And out of them a limited number of methods must be selected due to dominancy in these three points. Pro-jections which we can refer to in literature are about seven : 1) modified Water's, 2) transoral modified Water's, 3) Eraso's, 4) Chaussé II, 5) Fischgold's 6) Porcher's and 7) Terrahe's projections, respectively.

Among them Eraso's and Terrahe's projections can be prefered as the methods of choice for the diagnosis of the glomus jugulare tumor. As the foramen jugu-lare is projected by Eraso's method, the petrous bone which might be superimposed over the foramen by other projections and likely to make its contrast un-clear can be excluded from it. It can be probably advantageous to compair foramina of both sides on one film in this projection. It is, however, generally accepted that by comparing jugular foramina on both sides, man can not arrive at an exact diagnosis of the glomus jugulare tumor, because of the normal variety which may show a considerable difference in size between foramina of both sides. In an earlier stage of this tumor a tiny, bony structure of the fo-ramen covering the endocranial opening of the canal, i. e. incisura jugularis in the fossa jugularis will solely be destructed. By this reason, Terrahe's projection that is a lesser angle tomoraphy is able to make a contrast to this fossa jugularis and a necessary the method of choice for the diagnosis of the glomus tumor, especially of the earlier stage.