Thyroid hemiagenesis: case report and review of literature

ABSTRACT

Thyroid hemiagenesis is a rare embryological condition in which the left lobe is usually absent. The remaining thyroid lobe may present as benign adenoma, multinodular goiter, hyperthyroidism, chronic thyroiditis, hypothyroidism and rarely carcinoma. The most common pathology involved in thyroid hemiagenesis is hyperthyroidism. This report probably represents the first ever reported case of thyroid hemiagenesis from Kuwait. This 56-year-old Kuwaiti male presented with a left thyroid swelling, a history of progressive fatigue, constipation and weight gain, and exercise intolerance. The patient's preoperative workup included an ultrasound scan, thyroid scan, computed tomography [CT] scan and thyroid profile. His T4 was 3 pmol/ 1 and TSH was 200 uUI/ml. All investigations revealed a multinodular goiter in the left lobe with an absent right lobe. A fine-needle aspiration biopsy was suspicious for malignancy. The patient underwent left thyroid lobectomy. The operative findings confirmed hemiagenesis of the right lobe and histopathology showed benign multinodular goiter in the left lobe. The parathyroids on the left side were in the normal position. This case report presents a rare case of hypothyroidism and absent right thyroid lobe. It may help increase awareness of this rare anomaly of the thyroid gland and thus make preoperative diagnosis possible