Endocrine Abstracts

Introduction: Primary parathyroid carcinoma accounts for less than 1% of the parathyroid gland tumours and almost always presents as primary hyperparathyroidism. Very few Turner syndrome patients have been reported so far to present with primary hyperparathyroidism secondary to parathyroid adenoma. We report a case of parathyroid carcinoma in a 59 years old lady with Turner syndrome who is presenting with recurrent mild hypercalcemia.

Case presentation: A 59 years old lady with Turner syndrome under the dedicated Endocrine Service for her long term surveillance. She firstly presented in 2008 with elevated calcium of 3.00 mmol/l and PTH just above the upper border of normal. Sestamibi and ultrasound parathyroid identified parathyroid adenoma in the inferior pole of the left lobe of the thyroid and given persistent hypercalcaemia she underwent parathyroidectomy. Histology revealed parathyroid adenocarcinoma and patient then underwent elective left hemithyroidectomy. Her calcium profile and PTH remained stable for 11 years but in 2019 she was found presenting with recurrent hypercalcemia with corrected calcium of 2.64 mmol/l, phosphate 1.12 mmol/l, PTH 3.0 pmol/l and vitamin D 75 mmol/l against a normal kidney functions and bone density scan. She was further investigated with US parathyroid and CT parathyroid that did not demonstrate any parathyroid adenoma. Her urinary calcium output was 7.2 mmol/24 hour with a calcium creatinine clearance ratio of 0.04. She was further discussed in parathyroid MDT and monitoring of calcium with surveillance scan was suggested. Patient remains completely asymptomatic from her hypercalcemia.

Conclusions: This is a unique case of Turner syndrome with mild hypercalcemia on the background of hemithyroidectomy for parathyroid carcinoma who remains currently asymptomatic. She continues to have biochemical and radiological monitoring.