Endocrine Abstracts

: Primary hyperparathyroidism (PHPT) is a common endocrine condition but is relatively rare in very young people and during pregnancy. The diagnosis in pregnancy poses a unique challenge and is often missed as the symptoms of hypercalcemia mimic those in pregnancy. We present the case of a 20-year old woman who was found to have severe hypercalcemia after she had persistent vomiting in early pregnancy. Biochemistry revealed adjusted calcium of 5.34 mmol/L, parathormone of 103.9 pmol/L and normal Vitamin D. Further investigations revealed hypercalciuria, renal impairment and renal medullary calcification. She was fluid resuscitated aggressively. She decided to undergo medical termination of this unplanned unwanted pregnancy at nine weeks gestation. She was commenced on cinacalcet but hypercalcaemia remained refractory. She had no family history of hypercalcemia or multiple endocrine neoplasias. Neck ultrasound and sesta-MIBI failed to localize a parathyroid lesion. Subsequent 4-D CT and methionine PET revealed a large mediastinal ectopic parathyroid lesion. She had parathyroidectomy at thoracic surgery centre and calcium normalized after surgery. This case highlights the challenges in diagnosis, investigation and management of PHPT in pregnancy. The diagnosis needs a high index of suspicion. In our case, detailed probing revealed an 18-month history of weakness, polyuria, nocturia, vomiting, and memory impairment. Localization of abnormal parathyroid glands is difficult as ultrasound is the only safe imaging. Most calcium-lowering drugs are contraindicated, with rehydration being the mainstay of treatment. If parathyroidectomy is indicated, it is best performed in second trimester when organogenesis is complete and the risk of preterm delivery relatively low.