Endocrine Abstracts

Introduction: Primary hyperparathyroidism (PHPT) is a common endocrine disorder. It is most often caused by one or more autonomously functioning parathyroid adenomas (up to 85%), less commonly by parathyroid hyperplasia (<15%), and rarely (1–2%) by parathyroid carcinoma. Spontaneous remission due to necrosis, haemorrhage, or infarction of a parathyroid adenoma—referred to as “parathyroid auto-infarction” or “parathyroid apoplexy” is rare. We present a case of suspected parathyroid auto-infarction managed conservatively with clinical and biochemical surveillance.

Case Presentation: A 72-year-old woman was diagnosed with PHPT in 2013, based on persistent hypercalcaemia (2.70–3.09 mmol/l), elevated PTH levels (7.2–13.1 pmol/l). Conservative management was initially recommended. She was lost to follow-up. Re-referred in 2021 after sustaining a left wrist fragility fracture. DEXA scan showed progression from osteopenia (2013) to osteoporosis (T-score -2.5). Kidney ultrasound revealed stones. Surgical management was considered. However, initial localisation studies (ultrasound and MIBI scans) were inconclusive. PET-CT performed for a lung nodule incidentally identified a 9mm parathyroid adenoma anteroinferior to left thyroid and a second 9mm ectopic adenoma in anterior mediastinum. She was referred for surgery, but a review in February 2023—prior to further intervention—revealed unexpected normalisation of calcium (2.47 mmol/l), PTH (4.3 pmol/l), and low fractional calcium excretion (0.07%), with optimal vitamin D levels (84.6 nmol/l) (eGFR 78). Her biochemistry has remained normal since. She reported no symptoms of neck pain or dysphagia.Most plausible explanation for this spontaneous resolution is auto-infarction of a parathyroid adenoma. She remains under close follow-up with biochemical monitoring every 3–4 months.

Conclusion: Parathyroid auto-infarction should be considered in cases of spontaneous PHPT resolution. Though rare, recurrence is well-documented, making long-term clinical and biochemical surveillance crucial. While surgery is often recommended following auto-infarction, selected patients—like this case -may be managed conservatively with close monitoring.