Summary

We report the case of two patients with newly diagnosed primary hyperparathyroidism: a 40-year-old woman during pregnancy and a 60-year-old man with initial hypercalcaemic crisis. In the first case, a bilateral neck exploration with parathyroidectomy during the second trimester of pregnancy was unsuccessful and the patient remained hypercalcaemic. Postpartum imaging assessment with technetium (^99mTc)-sestamibi scintigraphy could not supply conclusive diagnostic results. The use of ¹⁸F-fluorocholine (FCH) positron emission tomography (PET)/CT provided the accurate localisation of an ectopic parathyroid adenoma in the anterior mediastinum which was successfully resected by a thoracoscopic approach. In the second case, ^99mTc-sestamibi scintigraphy was inconclusive as well and FCH-PET/CT localised an ectopic parathyroid adenoma in the mediastinum and thus bilateral neck exploration could be spared. Both patients had surgical cure of their disease.