Endocrine Abstracts

Introduction

Parathyroid carcinoma is a very rare phenomenon with an estimated prevalence of 0.005% of all cancers. There have been fewer than ten cases of parathyroid carcinoma in pregnancy previously reported in literature. Clinical features are similar to primary hyperparathyroidism and the diagnosis is usually made on surgery or histology. We present a unique case of parathyroid carcinoma in pregnancy where ventricular bigeminy was the presenting feature.

Case report

A 38-year-old multiparous woman presented to the emergency department with severe palpitations in the second trimester of her fifth pregnancy. She also had headaches, dizziness and polydipsia. Admission laboratory results revealed severe hypercalcaemia (3.07 mmol/l), raised PTH (87 ng/l) and a mild hypophosphatemia (0.79 mmol/l). 12-lead ECG showed ventricular bigeminy. Initial management comprised of intravenous rehydration and beta-blockers. Further investigations included a 24-h ECG recording which showed ventricular bigeminy and high frequency premature ventricular contractions amounting to a burden of 26%. Echocardiography demonstrated a mildly dilated right atrium with good biventricular function. Neck ultrasound revealed a lesion in the posterior aspect of the right lobe of the thyroid. Despite drinking copious amount of fluids at home, she continued to have severe hypercalcaemia needing multiple hospital attendances for intravenous rehydration. Her case was reviewed in the endocrine multidisciplinary meeting where surgical management during pregnancy was deemed most appropriate given her recurrent hospital admissions and potential risks to foetal wellbeing. Consequently, she underwent a right unilateral neck exploration at 23 weeks gestation. Intraoperative concerns of cancer led to an en-bloc resection of the right parathyroid and thyroid lobe. Histology results confirmed parathyroid carcinoma. Post-operatively, the patient recovered well and was biochemically hypothyroid thus treated with Levothyroxine. Gene testing did not reveal any known genetic causes of parathyroid carcinoma. She had regular growth scans, calcium and TSH monitoring for the remainder of the pregnancy and underwent an uncomplicated caesarean section (patient preference) at 39 weeks.

Conclusions

The vague nature of symptoms, entwined with overlapping features of pregnancy makes recognition of parathyroid carcinoma in pregnancy challenging. To our knowledge, this is the first case of parathyroid carcinoma presenting as ventricular bigeminy and highlights several key points. Firstly, the importance of early recognition and timely surgical management in reducing maternal and foetal complications. In addition, it illustrates the value of interprofessional collaboration between different specialities to provide good quality care and ensure optimal outcomes in potentially challenging and rare diseases.