A Case of a Bronchial Foreign Body (Artificial Tooth) in the Right Middle Bronchus Without Respiratory Symptoms

気管支異物は咳嗽を主とした自覚症状を呈し，しばしば摘出に難渋する．介在部位としては右下葉支が最も多く，右中葉支は稀である．症例は85歳，男性．自覚症状はなかった．前日に歯科治療中に義歯を誤嚥し，近医を受診した．胸部X線写真で右中下肺野に異物を指摘され，当科を受診した．胸部CTでは，右中葉支に気管支異物を認め，同病変の周囲にアーチファクトを伴っており，義歯の金属片と考えられた．3次元再構成画像では，右中葉支中枢側に義歯の歯根部を確認でき，侵襲性を考え，軟性気管支鏡下に摘出を行う方針とした．気管支鏡検査では，右中葉支を閉塞するように金属片を認めたが，肉芽形成は伴っておらず，鰐口鉗子を用いて歯根部を把持し，速やかに摘出を行うことができた．呼吸器症状を伴わない，右中葉支に介在した気管支異物の一例を経験した．高齢者では呼吸器症状を伴わないこともあるため，画像検査を行うことが重要である．Patients with bronchial foreign bodies often present with subjective symptoms, mainly cough, and removing the foreign bodies is difficult. Bronchial foreign bodies are mostly located in the right lower bronchus, and rarely in the right middle bronchus. An 85-year-old man had no subjective symptoms. He aspirated an artificial tooth during dental treatment the day before visiting our clinic, and consulted his home doctor. He was admitted to our hospital because a chest radiograph indicated the presence of a foreign body in the right middle and lower lung field. Chest computed tomography showed that the bronchial foreign body was located in the right middle bronchus, and it was accompanied by an artifact in the circumference of the lesion, and it seemed to be the metal piece of an artificial tooth. Three-dimensional CT showed the root of the artificial tooth located in center side of the right middle bronchus, and, considering the invasiveness, we decided to remove the tooth by flexible bronchoscopy. The bronchoscopy revealed a metal piece occluding the right middle bronchus without granulation, and we could remove the tooth immediately by grasping the root of the tooth with alligator forceps. We experienced a case of a foreign body located in the right middle bronchus without respiratory symptoms. It is important to carry out image examinations, because elderly patients may not exhibit respiratory symptoms.