Treatment of a nonfunctioning parathyroid cyst with tetracycline injection

Abstract

Parathyroid cysts are uncommon: about 200 cases have been reported. They can be functional (i.e., accompanied by signs of primary hyperparathyroidism), or nonfunctional. Preoperative diagnosis is difficult, although it has become increasingly frequent with the use of ultrasound and fine-needle aspiration biopsy. Fluid of parathyroid cysts is almost invariably watery, colorless, and crystal clear, which should cause clinical suspicion. However, definitive diagnosis relies on the demonstration of high parathyroid hormone (PTH) levels in the fluid. Puncture may cure nonfunctioning cysts, but surgery is indicated when the lesion recurs after several fine-needle aspirations. We report a case of a nonfunctioning parathyroid cyst in a 17-year-old boy, which reappeared after two punctures made 6 months apart. On the third occasion, 1 mL of a sterile tetracycline solution injected into the cyst cured the lesion. Tetracycline and other sclerosants have been recommended as a treatment of recurring thyroid cysts. We suggest that injection of a sclerosant should be considered as an alternative to surgery in recurring, nonfunctional cysts of the parathyroid glands.

A rare case of a parathyroid adenoma inside a parathyroid cyst

“…In case of recurrence (16), sclerotherapy with tetracycline and alcohol can be effective, but may result in fibrosis and recurrent laryngeal nerve palsy (17). Simple observation can be suggested for small, asymptomatic PCs.…”

Diagnosis and Therapeutic Management of Parathyroid Cysts

“…Fine Needle Aspiration allows the diagnosis between rarer parathyroid cysts and thyroid cysts, which are often falsely suspected, to be made [5,8,17,20,23]. In thyroid cysts the intracystic level of thyroid hormones and thyroglobulin is raised while the level of PTH is zero [8,20,27].…”

“…In these cases surgery [3,8,20,22,28] repeated fine needle aspiration until the cyst disappears [1,2,23] or intracystic injections to cause sclerosis (tetracycline [27] or ethanol [3,4]) can then be considered. Intracystic injections are accompanied by pain, fever and transient breathlessnesss in 5% of cases [4,6,20].…”

“…It is for this reason that Verges et al advise that whilst carrying out the technique one should speak to the patient and, at the slightest suggestion of dysphonia, should stop the procedure (4 transient dysphonias out of 13 patients in their trial) [29]. It appears that recovery can be established without the need for subsequent sclerosing injections [27,28].…”

“…In the context of an active parathyroid cyst surgical excision seems the obvious choice [1,2,5,7,13,27] with an extemporaneous histological examination of the surgical specimen. This dissection can be difficult due to the hypervascular character of the cyst and the fact that it can be embedded in the thyroidal parenchyma which can lead to associated resection of the thyroid gland [30].…”