Thyroid hemiagenesis

Thyroid hemiagenesis is a rare developmental anomaly of the thyroid gland seldom diagnosed except by thyroid scan or during surgery. A high index of suspicion can lead to the diagnosis with little difficulty. We herein describe the case of a thirteen year old girl who presented with a right side neck swelling. Isotope thyroid scan demonstrated a localized right thyroid lobe nodule with no uptake in either the isthmus or the left lobe. A subtotal thyroidectomy was done for the right lobe goitre and histopathology revealed normal thyroid tissue with colloidal mirco-follicular cysts