Cyst fluid from a parathyroid cyst
A single-institution 25-year review of true parathyroid cyst
Ippolito, G., Palazzo, F.F., Sebag, F. et al. Langenbecks Arch Surg (2006) 391: 13. doi:10.1007/s00423-005-0579-y
Parathyroid cysts (PCs) are rare, and their origin is a subject of debate. They have been described as either functional, causing hyperparathyroidism, or non-functional in eucalcaemic patients.
Patients and methods
We have performed a 25-year departmental review of PCs. Features studied included the clinical presentation and intra-operative findings, and a histological review was performed. Cases of cystic degeneration of parathyroid adenomas and pseudocystic change were excluded.
Over 25 years, 22,009 thyroidectomies and 2,505 parathyroidectomies were performed in our department. Amongst these, 38 non-functional PCs were documented in 37 patients. The mode of presentation included incidental findings on routine chest x-ray, compressive symptoms or an asymptomatic palpable neck mass. Aspiration was the initial treatment in 14 patients and was curative in 10 of these. Four out of 14 patients underwent surgical procedures for recurrence of the cyst that occurred 6 to 48 months after aspiration. In 27 patients, surgery was performed and all identified PCs were localized in the inferior parathyroid glands. Histologically, the cyst wall consisted in associations of lymphoid, muscular, thymic, salivary, adipose and mesenchymal tissues.
PCs are rare but should be included within the differential diagnosis of a neck lump. True PCs are non-functional. Pathological and immunohistochemical findings are suggestive of a branchial origin. Fine-needle aspiration may be curative and is diagnostic due to the characteristic appearance of the fluid and high PTH levels on assay.
Comment: Now with high frequency ultrasound we see smaller parathyroid cysts that may not need any treatment unless they bleed and cause pain. The fluid may not always be clear.If there is a bleed the fluid may be red or brownish.Parathyroid cysts may be located in the thyroid gland. Thyroglobulin /parathyroid hormone needle washouts can tell if it is a intrathyroidal parathyroid cyst or adenoma.
Richard Guttler MD,FACE,ECNu