A rare case of a fish bone penetration into the thyroid gland from the esophagus is reported. A 70-year-old woman visited a local practitioner because of cervical pain and low grade fever 5 days after she had swallowed a fish bone, and was referred to the hospital with a diagnosis of fish bone stuck in the esophagus. X ray examination of the neck revealed a lineal calcification in the cervical region, and a CT scan visualized a low density area including a lineal high density foreign body beneath the thyroid gland. Ultrasonography also detected a linear strong echo. Under a diagnosis of a fish bone stuck in the thyroid gland and a cervical abscess, an operation was started by a Kocher's incision. The fish bone was penetrated into the right lobe of the thyroid gland, and the esophagus was intact. A removal of the fish bone, a partial resection of the thyroid gland and suction drainage were performed. Postoperative course was uneventful and the patient was discharged from the hospital on the 21st postoperative day.
An endoscopic removal of the a fish bone stuck in the esophagus is often successful, however, there are a few cases in which perforation or penetration of the esophagus due to the fish bone will occur. CT and ultrasonography are useful for diagnosis and treatment of perforation or penetration of the esophagus due to fish bones.