The signet-ring formation of follicular cells is uncommon morphology. So, signet- ring cell adenoma of the thyroid is extremely rare. A 60-year-old male presented with stinging pain in neck and hoarseness that have been continuing for 2 years. The ultrasonography detected a nodule which was 23×21x24 mm in size on the left lobe of thyroid. Then, pyramidal lobe and left lobe were removed. Pathological examinations identified this adenoma as signet ring cell adenoma. We represent signet-ring cell adenoma of thyroid gland in this case report.
Keywords: Thyroid follicular adenoma, cytology, signet-ring cell