Abstract
Background In recent years, incidence and prevalence of thyroid and extrathyroid lesion is increasing in the worldwide due to increase awareness of medical check-up, and widespread use of imaging techniques. A Killian Jamieson diverticulum (KJD), a rare type of hypopharyngeal pulsion diverticulum outpouching from the lateral wall of the proximal cervical esophagus, was incidentally detected and likely to be misinterpreted as a thyroid nodule while performing thyroid sonography. Clearly differentiate between those lesions is essential to avoid unnecessary invasive procedure. Here we report a typical case of bilateral Killian Jamieson diverticulum mimicking thyroid nodules. Clinical case A 57-year-old Taiwanese man was referred to our endocrine outpatient department for further evaluation of thyroid nodules. The lesions were discovered while sonographic examination performed in the clinic for routine medical check-up. He denied having dysphagia, epigastric pain, odynophagia, halitosis, chronic cough or acid regurgitation, body weight loss, fever and dyspnea. He had no previous systemic disease and no prior radiation therapy. He lives in Nangang District, Taipei city. His body weight was 70 kg and BMI was 25. An examination of head and neck was unremarkable. Laboratory data revealed normal thyroid function (TSH: 0.67 uIU/ml; range 0.4~4.0, free T4: 0.83 ng/dl; range 0.9~1.8 and aTPO <1.0 IU/ml; range <5). Thyroid ultrasonography demonstrated oval, hypoechoic nodule-like lesions containing bright foci with acoustic shadow in the posterior aspect of the both lobes of thyroid gland. The rest of thyroid glands were normal appearance. An esophagography was performed and showed two contrast-filling anterior outpouching lesions at both sides of the cervical esophagus, around C7 level and both lesions were showing anterior outpouching appearance, consider Killian-Jamieson diverticulum. Taken together, he was diagnosed as KJD and clinical follow-up alone is suggested. Clinical lessons KJD is usually incidentally detected and misdiagnosed as a thyroid nodule containing punctuate microcalcification foci as found in papillary thyroid carcinoma. To differentiate these nodules, real time sonographic examination is important. Although rare, non-thyroid lesions originating from the esophagus should be considered in the differential diagnosis of the thyroid nodules to avoid unnecessary invasive fine needle aspiration of thyroid gland.