眼窩リンパ増殖性疾患85例のMRI画像の検討

Magnetic resonance imaging of orbital lymphoproliferative diseases

要約　目的：眼窩リンパ増殖性疾患のMRI所見の報告。対象：過去12年間にさいたま赤十字病院で病理学的に眼窩リンパ増殖性疾患と診断された85例を対象とした。悪性リンパ腫，反応性リンパ過形成，特発性眼窩炎症，IgG4関連疾患を本症と定義した。結果：男性46例，女性39例で，年齢は25～92歳，平均62歳であった。内訳は悪性リンパ腫48例，反応性リンパ過形成22例，特発性眼窩炎症6例，IgG4関連疾患9例で，片側性59例，両側性26例であった。両側性は特発性眼窩炎症とIgG4関連疾患に多かった。37例（44％）では眼窩内の耳上側に発症した。眼球変形はびまん性大細胞型B細胞リンパ腫4例に認めた。外眼筋肥大が18例にあり，悪性リンパ腫11例とIgG4関連疾患4例を含んでいた。結論：MRI検査は，両側発症の有無，眼窩内の部位，眼球変形の有無，外眼筋肥大などに関する情報を提供し，眼窩リンパ増殖性疾患の診断に有用である。

Abstract.　Purpose：To report findings by MRI（magnetic resonance imaging）of orbital lymphoproliferative diseases. Cases：This retrospective study was made on 85 cases who were histopathologically diagnosed with lymphoproliferative disease during the past 12 years. Results：The series comprised 46 males and 39 females. The age ranged from 25 to 92 years, average 62 years. There were malignant lymphoma 48 cases, reactive lymphoid hyperplasia 22 cases, idiopathic orbital inflammation 6 cases, and IgG4-related disease 9 cases. The orbit was involved unilaterally in 59 cases and bilaterally in 26. Bilateral cases were more frequent in idiopathic orbital inflammation and IgG4-related disease. The tumor was mainly located superior-temporally in the orbit in 37 cases（44％）. The eyeglobe was deformed in 4 cases of diffuse large B-cell lymphoma. Hypertrophy of extraocular muscles was present in 18 cases, including 11 cases of malignant lymphoma and 4 cases of IgG4-related disease. Conclusion：MRI was useful in the diagnosis of orbital lymphoproliferative diseases, as it gave informations regarding bilateral involvement, location in the orbit, deformation of eyeglobe, and hypertrophy of extraocular muscles.