逆V字型FDG集積はIgG4関連前立腺炎診断の手がかりとなる

Inverted-V shaped FDG uptake is a clue for the diagnosis of IgG4-related prostatitis

IgG4関連疾患はここ十数年間において確立した疾患概念であり，リンパ球とIgG4陽性形質細胞の著しい浸潤および花筵状線維化に代表される特徴的な線維化パターンを伴う腫瘤性・肥厚性病変をきたす全身疾患である。この概念には唾液腺におけるミクリッツ病やキュットナー腫瘍，膵における自己免疫性膵炎，血管系における炎症性動脈瘤やその周囲に生じる後腹膜線維症など各臓器における様々な疾患が含まれ，かつて単一臓器・器官における病態として診断されていたこれらは今や共通の全身性病態によるとみなされる^1）。

We investigated the utility of inverted-V shaped FDG uptake in the PET diagnosis of IgG4-related prostatitis. For 25 males with IgG4-related disease（IgG4-RD）and 22 males with benign prostatic hyperplasia who had PET/CT checkup, the shape of prostatic uptake were compared as well as prostatic SUVmax. Then SUVmax was compared using ANOVA among the IgG4-RD cases with inverted-V uptake, those without inverted-V, and the controls. 10/25 IgG4-RD cases and 0/22 controls had inverted-V shaped uptake. Their SUVmax had a substantial overlap. ANOVA showed significant difference among the 3 groups, and inverted-V（＋）cases had significantly higher SUVmax than inverted-V（−）IgG4-RD cases and the controls. Inverted-V uptake is useful for IgG4-RD diagnosis.