特徴的な4D-CT angiography像を呈したidiopathic myointimal hyperplasia of mesenteric veinsの1例

Idiopathic Myointimal Hyperplasia of Mesenteric Veins with Characteristic 4D Computed Tomographic Angiography Findings, Report of a Case

要旨●患者は70歳代，女性．下痢，粘液便，腹痛にて当科を受診し，左下腹部に有痛性腫瘤を認めた．S状結腸憩室炎と診断し抗菌薬治療で腹痛は軽快したが，下痢が遷延した．大腸内視鏡検査でS状結腸を中心に発赤浮腫状粘膜を背景にびらんと炎症性ポリープを認め管腔は狭窄していた．腸間膜脂肪織炎を疑い，ステロイド治療を行うも改善せず外科的切除を施行した．切除標本の病理組織像で腸間膜静脈筋内膜過形成と内腔狭窄・閉塞を認めIMHMVと最終診断した．術前4D-CT angiographyを見直したところ，腸間膜静脈の動脈相での早期造影や腸間膜動脈との動静脈瘻形成，腸間膜静脈の造影剤滞留と動脈瘤様変化，下腸間膜静脈閉塞所見を確認できた．

　A woman in her 70s presented to our hospital with diarrhea, mucus in stool, and abdominal pain, and physical examination revealed a palpable mass with pain on rebound in left lower abdomen. She was diagnosed with sigmoid diverticulitis based on CT findings and treated with antibiotics, which alleviated abdominal pain, but the diarrhea persisted. Colonoscopy revealed erosions and inflammatory polyps against a background of reddish, edematous mucosa primarily in the sigmoid colon, and the colon lumen was narrowed. Mesenteric panniculitis was suspected, and her clinical condition did not improve despite steroid treatment, requiring surgical resection of descending colon to sigmoid colon. The definitive diagnosis was idiopathic myointimal hyperplasia of mesenteric veins with luminal stenosis/occlusion based on histologic evaluation of the resected specimen. Review of the results of preoperative 4D computed tomographic angiography of the mesenteric veins revealed early contrast enhancement in the arterial phase, an arteriovenous fistula with the mesenteric artery, contrast medium stagnation, aneurysm-like changes, and occlusion of the inferior mesenteric vein.