Parathyroid adenomas: pre-operative localization with ultrasound combined with fine-needle biopsy.

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.