RESUMO
OBJECTIVE: Determine a means of establishing the diagnosis of parathyroid cysts preoperatively. PATIENTS AND METHODS: Classically, crystal-clear watery fluid removed by fine-needle aspiration of a suspected thyroid mass raises the suspicion of a parathyroid cyst. Immunoradiometric assay of parathyroid hormone level in the fluid may give the diagnosis sparing unnecessary surgery. RESULTS: Over the last 5 years, among the 12 patients presenting a suspected thyroid cyst containing a crystal-clear fluid, we were able to diagnose 3 cases of parathyroid cysts due to the considerable elevation of parathyroid hormone in the puncture fluid. None of these patients had hyperparathyroidism. In patients with a thyroid cyst, parathyroid hormone level in the puncture fluid was nil. CONCLUSION: The parathyroid nature of cervical cysts containing crystal-clear fluid can be established by assaying parathyroid hormone in the puncture fluid. Non-functional parathyroid cysts may be treated by repeated aspiration. Serum calcium level must be checked regularly to detect potential hyperparathryoidism.
