Septic thrombophlebitis of the inferior mesenteric vein and associated mesenteric abscess complicating sigmoid diverticulitis: A case report

Thrombophlebitis occurs secondarily to inflammatory conditions of adjacent organs, and radiologic finding is essential for diagnosis. However, because of the rarity on clinical cases that involve the inferior mesenteric vein, many radiologists are unfamiliar with its location and appearance. We experience a case of septic thrombophlebitis with abscess complication sigmoid diverticulitis. CT scans reveals a low density thrombus and air in the inferior mesenteric vein, combining with perivascular fat infiltration, and focal wall defects with abscess formation. After surgical treatment, the abscess was not visible in the follow-up CT scans. Septic thrombophlebitis of the inferior mesenteric vein, although being a rare disease, should be diagnosed on CT according to the given unique location, the appearance of inflamed vein and the adjacent descending mesocolon.