Toxic Adenoma in a Patient with Thyroid Hemiagenesis

Colloid nodular goitre associated with hemiagenesis of the thyroid gland

Hemiagenesis of the thyroid gland is a rare congenital abnormality usually left unnoticed without associated thyroid disorders. The most common congenital anomaly of the thyroid gland is a thyroglossal cyst, followed by ectopic thyroid tissue and thyroid dysgenesis, which may be agenesis or hemiagenesis. Preoperative underevaluation of the thyroid hemiagenesis (THA) associated with other thyroid disorders may cause intraoperative difficulty in identifying the gland and difficulty in preservation or even identification of major neurovascular structures during neck exploration. We report a patient who presented to us with right-sided neck swelling. On further evaluation and neck exploration, the patient was diagnosed with THA of the left lobe with right colloid goitre.

Thyroid hemiagenesis with a TI-RADS 2 nodule in the contralateral lobe

Background

Thyroid hemiagenesis is a rare congenital anomaly in which one lobe of the thyroid gland fails to develop. There is an increased incidence of associated thyroid disorders in patients with thyroid hemiagenesis.

Case presentation

A 32-year-old Ugandan woman presented with a complaint of painless neck swelling of 3-months duration. The swelling was associated with a globus sensation. There was no history of thyroid – related problems or treatment prior to this presentation. Physical examination demonstrated a mobile right thyroid swelling without an obvious nodular contour. Neck ultrasound showed an absent left lobe of thyroid gland, a right lobe with a solitary nodule scoring two points on the Thyroid Imaging, Reporting and Data System (TI-RADS) and an isthmus in situ. Extensive search for possible ectopic thyroid tissue was negative. She was biochemically euthyroid. The patient was counseled about thyroid hemiagenesis and was put on a regular follow up in the clinic for the TI-RADS 2 nodule.

Conclusion

Thyroid hemiagenesis is often associated with other thyroid disorders. Its diagnosis should prompt an active search for other associated morphological or functional thyroid abnormalities.