ESA-SRB-AOTA 2019

When the stakes are high but the calcium is higher (#647)

Linda Wu 1 , Mark Sywak 2 3 , David Marshman 4 , Sean Seeho 3 5 , Jeremy Hoang 1 6 , Tang Wong 7 , Venessa Tsang 1 3
  1. Department of Endocrinology, Royal North Shore Hospital, St Leonards, NSW, Australia
  2. Department of Endocrine Surgery, Royal North Shore Hospital, St Leonards, New South Wales, Australia
  3. Northern Clinical School, University of Sydney, Sydney, NSW, Australia
  4. Department of Cardiothoracic Surgery, Royal North Shore Hospital, St Leonards, NSW, Australia
  5. Department of Obstetrics and Gynaecology, Royal North Shore Hospital, St Leonards, New South Wales, Australia
  6. Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, New South Wales, Australia
  7. Department of Endocrinology, Prince of Wales Hospital, Randwick, NSW, Australia

A 33 year old primigravid woman was referred for endocrine review for asymptomatic hypercalcaemia at 8 weeks gestation. Serum corrected calcium was 2.66 mmol/L with an inappropriately raised parathyroid hormone (PTH) 76ng/L (10-65ng/L) and raised 24hr urine fractional excretion of calcium (FECa) of 0.05. Calcium progressively rose to 2.9 mmol/L by 22 weeks gestation. Neck ultrasound showed multiple thyroid nodules with the dominant nodule having Bethesda category IV cytology however no parathyroid adenoma visible. Neck exploration and right hemithyroidectomy was undertaken at 24 weeks gestation with 4 glands visualised and 2 parathyroid glands resected. Histopathology revealed 2 fat replete parathyroid glands, 23mm follicular carcinoma and a focus of papillary microcarcinoma. Calcium and PTH transiently normalised but by 25 weeks gestation cCa was 2.96mmol/L and PTH 85ng/L. A low dose Sestamibi scan was performed and localised a posterior mediastinal parathyroid adenoma at T4 level. A multidisciplinary decision was made to proceed with hemisternotomy at 26 weeks gestation with successful resection of a 975mg fat deplete parathyroid adenoma. Post-operative PTH was low initially and subsequently normalised and calcium levels remained within normal limits.

Discussion

Primary hyperparathyroidism in pregnancy carries significant risks, with a recent case series reporting preeclampsia in 30% of medically managed patients and preterm delivery in 66%1. Key considerations for surgical resection of parathyroid adenoma in pregnancy include gestational age, localisation modalities with radiation exposure in pregnancy and in the case of ectopic adenoma, surgical feasibility. This is the second case ever published where sternotomy has been successfully performed for treatment of ectopic parathyroid adenoma in pregnancy2.

Conclusion

Ectopic parathyroid adenoma in pregnancy are a high risk situation where risks of surgery need to be carefully weighed with risks of hypercalcaemia and maternal and fetal wellbeing.

  1. Rigg J, Gilbertson E, Barrett HL, Britten FL, Lust K. Primary Hyperparathyroidism in Pregnancy: Maternofetal Outcomes at a Quaternary Referral Obstetric Hospital, 2000 Through 2015. J Clin Endocrinol Metab. 2019;104(3):721-729.
  2. Rooney DP, Traub AI, Russell CF, Hadden DR. Cure of hyperparathyroidism in pregnancy by sternotomy and removal of a mediastinal parathyroid adenoma. Postgrad Med J. 1998;74(870):233-234.