Primary hyperparathyroidism during pregnancy carries significant risks to both mother and fetus. Parathyroidectomy remains the only definitive treatment for the condition. The timing of surgery remains controversial, with ongoing debate regarding the safety of surgery during the third trimester. A case of symptomatic primary hyperparathyroidism treated by parathyroidectomy in the third trimester is described. The clinical features, investigations and treatment options are discussed.

The brown tumour of hyperparathyroidism is a localized bone tumour and an uncommon manifestation of hyperparathyroidism. A 27-year-old woman presented with a mandibular 8 × 10 cm solid mass diagnosed as central giant cell granuloma. Chemical blood analysis revealed increased serum calcium levels of 12.46 mg/dL and the parathyroid hormone level was 124 pg/dL. The patient underwent surgery with removal of a parathyroid mass. Histologically, this parathyroid tissue was seen to be limited by a fibrous capsule with morphological features consistent with atypical parathyroid adenoma. The mandibular tumour has receded and the patient declined further procedures. This is the first case reported of brown tumour as the primary manifestation of an atypical parathyroid adenoma, a lesion that shares some features with parathyroid carcinoma without the unequivocal properties of malignancy.

Radiological findings including ultrasonography, computed tomography (CT) and Tc-99m sestamibi scintigraphy of a patient with multilocular giant parathyroid adenoma which caused hypercalcaemic crisis are presented. The location of the tumour by grey scale sonography, CT and Tc-99m sestamibi scintigraphy was not certain because the tumour was uncommon in shape, location, size and internal structure. Whereas, increased flow in the solid portion of the mass was demonstrated on power Doppler sonography, which proved to reflect abundant vessels in the adenoma in pathological findings.

Sixteen patients with biochemically proven primary hyperparathyroidism (PHPT) underwent ultrasonography (US), fine-needle aspiration (FNA) for cytologic sampling (n = 9), or intact parathormone assay (n = 3) before operation (n = 15) in order to determine the accuracy of the methods. Pre-operative US was found sensitive (100 per cent), but two thyroid lesions were initially diagnosed as parathyroid tumours by US (i.e. false positives). Parathyroid cells were detected in six cytologic specimens, one sample was insufficient and another inconclusive, while one was diagnosed as thyroid tissue. Parathormone assay revealed a high hormone content in all three patients who underwent the procedure. We conclude that US is sufficiently sensitive to detect enlarged parathyroid tumours. Specificity can be improved by US-guided FNA for cytology or parathormone assay prior to neck exploration.