Introduction: High-resolution ultrasound (US) allows the location of large parathyroid adenomas. These tumours should be however differentiated from thyroid nodules. For the confirmation of the parathyroid adenoma, we propose US-guided fine-needle aspiration biopsy (FNAB) of suspected nodules, with additional parathyroid hormone (PTH) analysis in the washout of the aspirate (PTH-FNA).
Case report: A 51-year old woman with recently installed menopause and a history of kidney lithiasis and fragility fractures attended our hospital for the investigation of a multinodular goitre. The measurement of bone mineral density assessed by dual X ray absorptiometry showed that the patient was severely osteoporotic, with lowest score on distal 1/3rd of the radius. Despite the presence of complications, the high PTH level (281 pg/ml) was accompanied by only marginally increased serum calcium (10.1 mg/dl). This discrepancy may be explained by the co-existence of D hypovitaminosis (11 ng/ml). Ultrasound investigation revealed the presence of a multinodular goitre containing five nodules, one of them showing features suggestive for a large parathyroid adenoma. We measured high PTH levels only in the FNAB washout from the suspected parathyroid adenoma, but not in that extracted from the largest of the other thyroid nodules. The patient was submitted to total thyroidectomy due to compressive complaints and excision of the parathyroid adenoma. Immediately after surgical intervention, the PTH levels normalised. Histology confirmed pre-surgical localization of the parathyroid adenoma and revealed that one of the thyroid nodules contained an in situ papillary carcinoma.
Conclusion: PTH-FNA is a reliable and possibly a more accurate and faster method than additional imaging techniques to localise a large parathyroid adenoma in patients with concomitant thyroid nodules.
Disclosure: This work was supported by the European Social Found, Human Resources Development Operational Programme 2007-2013 DocMed.net_2.0 is POSDRU 159/1.5/S/136893.