[A case of obstructive ventilatory disturbance caused by bronchial wall granulation due to a fish bone]

A 62-year-old man was admitted to Kawasaki Medical School Kawasaki Hospital after suffering from wheezing for one year. His chest X-ray film showed no significant findings in the lung fields and mediastinum. A chest CT film showed a small protrusion at the posterior wall of the right main bronchus. Bronchofiberscopy disclosed a polypoid tumor with a smooth surface in the right main bronchus, confirming the finding of the chest CT, and a restiform eminence at the truncus intermedius. The restiform eminence was revealed to be a fish bone after removal from the bronchus using the forceps of a bronchofiberscope. Histological examination of a bronchoscopic biopsy specimen from the tumor of the right main bronchus showed inflammatory granulation tissue. We confirm subsequently questioned the patient who revealed that he had aspirated another fish bone two months earlier, and we presumed that the tumor of the right main bronchus might be granulation tissue secondary to the impaction of a fish bone. The patient was not aware that he had aspirated a foreign body, but it was presumed that he had aspirated the fish bone one year earlier, coinciding with the onset of wheezing. Immediately after removal, his wheezing disappeared. Comparison of the results of pulmonary function tests after removal with those before showed improvement of V25/predicted V25 ratio from 24% to 72%, and improvement of V50/V25 ratio from 3.7 to 2.4. This is considered to be a rare case of bronchial granulation due to a foreign body, which was recognized as a small polypoid tumor by chest CT.