Bowel Obstruction due to Shiitake Mushrooms: Diagnostic Features on Computed Tomography

Shiitake mushrooms are edible mushrooms popular in East Asian cuisine. We herein report a 69-year-old man with abdominal distension and vomiting after ingesting several pieces of sautéed Shiitake mushrooms. Abdominal computed tomography (CT) revealed ring-shaped and crescent-shaped low-density objects (-100 to -300 Hounsfield units) in the ileum. Based on the specific shapes and CT numbers of the foreign bodies, he was diagnosed with small bowel obstruction due to Shiitake mushrooms. After conservative treatment, he passed four pieces of Shiitake mushrooms. Despite the rarity, the condition can be diagnosed before exploratory surgery by careful and detailed interpretation of CT findings.