Ipsilateral double parathyroid adenoma and thyroid hemiagenesis

Background/Aims: To describe a case of left thyroid dysgenesis, accompanied by ipsilateral double parathyroid adenomas in a setting of primary hyperparathyroidism, and to review the pertinent literature on the diagnosis of these rare clinical scenarios. Methods: Review of the English literature with addition of a case report. Results: Preoperative evaluation included both sestamibi and ultrasound evaluation of the neck. Fine-needle aspiration biopsies of what was thought to be two concerning thyroid nodules revealed potential double intrathyroidal parathyroid adenomas. Video-assisted exploration verified double parathyroid adenomas and revealed concomitant left thyroid lobe dysgenesis. Intact parathyroid hormone level returned to normal and a greater than 50% drop from baseline was achieved intraoperatively with subsequent long-term cure. Conclusions: Thyroid dysgenesis is a rare, poorly understood and potentially confusing variety of developmental anomalies, which can be associated with thyroid as well as parathyroid disease. Clinical diagnosis is highly dependent upon the clinician maintaining an index of suspicion for these anomalies, thorough physical examination and careful review of available imaging modalities, especially while investigating thyroid and parathyroid disorders.