Endocrine Abstracts

Hypoparathyroidism is a rare complication that may occur as a result of thyroid surgery, this typically occurs in the immediate postoperative period. While resolution of hypoparathyroidism usually occurs on an average of two months postoperatively, approximately 1.9% become permanent. The delayed appearance of hypoparathyroidism decades after surgery is exceptionally rare, with no previously documented cases of hypocalcaemia manifesting more than 40 years postoperatively. We present a case of an 82-year-old patient whom was referred for an incidentally detected low calcium level (1.93 mmol/L). She had undergone a total thyroidectomy 40 years earlier for a compressive goitre. Postoperatively, no calcium levels were documented, and the patient had remained largely asymptomatic throughout her life. Laboratory tests had revealed a parathyroid hormone (PTH) level of 3.0 pmol/L (inappropriately low), elevated phosphate (1.75 mmol/L), and adequate vitamin D levels. Although no histology results were available to confirm parathyroid preservation during surgery, the patient’s findings were consistent with a diagnosis of late-onset partial hypoparathyroidism. She was thereafter started on low dose of alfacalcidol to help regulate her calcium levels. This case highlights a rare presentation of delayed protracted post thyroidectomy hypoparathyroidism (> 40 years post operatively), that to our knowledge has never been reported before. There are currently no available guidance for long term monitoring for post thyroidectomy patients and periodic surveillance of calcium levels may be necessary considering hypoparathyroidism may occur even after protracted periods of time as described as the case above.