Parathyroid cysts

Fourteen new cases of parathyroid cyst are presented. Two distinct groups were identified: functioning and nonfunctioning. Patients with functioning cysts presented with hypercalcemia, tended to be men and were older. Patients with nonfunctioning cysts were all women, had normocalcemia and all presented with neck masses. Ultrasonography proved useful while radionuclide thyroid scans were often misleading. In the functioning group removal of parathyroid cysts resulted in postoperative normocalcemia in all cases. In the nonfunctioning cysts thyroid lobectomy was performed in five of six instances. Parathyroid cysts usually contain clear or serous fluid and are surrounded by a well-delineated plane of dissection. We believe that preoperative aspiration of cystic neck masses and consideration of the diagnosis of parathyroid cysts may avoid needless thyroid lobectomy.     

Treatment of a nonfunctioning parathyroid cyst with tetracycline injection

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.     

无功能性甲状旁腺囊肿：附15例报告

目的 了解无功能性甲状旁腺囊肿的临床特点,探讨其诊治方法.方法 对近16年来收治的无功能性甲状旁腺囊肿15例患者的临床资料进行回顾性分析研究.结果 术前均未获得诊断,均经术后病理检查证实.全组均行手术切除获得治愈,随访无复发.结论 对无功能性甲状旁腺囊肿,病理学检查是最可靠的诊断方法,针刺抽液测定PTH或细胞学检查有助于术前诊断.手术切除是最理想的治疗方法.     

A giant nonfunctioning parathyroid cyst

Summary A case of a giant nonfunctioning parathyroid cyst is presented. The diagnosis was missed preoperatively, due to unfamiliarity with this pathology. Functioning parathyroid cysts cause hyperparathyroidism and are easy to diagnose. Nonfunctioning parathyroid cysts produce only a mass in the neck, without other symptoms. From the literature it appears that they are seldom diagnosed preoperatively. However, aspiration of clear, colorless watery fluid should lead to a correct diagnosis. This case is interesting because of its rarity and of the giant size of the cyst. No evidence of a parathyroid cyst of these dimensions has been found in the literature. This case also proves that parathyroid cysts may recur after aspiration; thus aspiration is not always the definite treatment of these cysts.Paper presented at the Autumn Meeting of the Belgian Society for Plastic, Reconstructive and Esthetic Surgery, Leuven, Belgium, November 4, 1989 Offprint requests to: Prof. G. Matton     

Needle aspiration of nonfunctioning parathyroid cysts

Until recently, nonfunctioning parathyroid cysts were usually identified at operation for a presumed thyroid mass. Thyroid needle biopsy now allows their preoperative diagnosis and potential definitive treatment. This study reviews four patients with nonfunctioning parathyroid cysts treated during a two-year period. Three women and one man range in age from 28 to 70 years. Each presented with an asymptomatic thyroid mass ranging from 3 to 5 cm in length. None had symptoms of primary hyperparathyroidism. Serum calciums were from 9.2 to 10.7 mg/dl and serum phosphoruses were 3.2 to 4.4 mg/dl. Needle aspiration revealed 5 to 85 cc of water-clear fluid. C-terminal parathyroid hormone in three patients was 12,600, 6,500 and 61,200 pg/ml and N-terminal PTH was 1,700 pg/ml in one. All four had normal serum calcium and phosphorus on follow-up ranging from six months to two years. Two patients had resolution of their cysts with a single aspiration. One patient had recurrence but has no evidence of recurrence six months after injection with tetracycline. Another patient had a recurrence but remains well one year following reaspiration. Nonfunctioning parathyroid cysts present as a thyroid mass. Needle aspiration of water-clear fluid high in parathormone is diagnostic and, in most patients, is the therapeutic modality of choice.     

Parathyroid cysts]

The Authors review the world literature on parathyroid cysts and report a case of this uncommon disease. The importance of an early pre-operative diagnosis by ultrasound, blood calcium level and parathyroid hormone assay with fine needle aspiration biopsy is pointed out. According to several surgeons, only the functioning parathyroid cysts require operation; needle aspiration may be appropriate therapy for the nonfunctioning ones.     

Parathyroid cysts

Cystic neck masses may be accurately diagnosed by sonography, and some nonfunctioning parathyroid cysts can be cured by percutaneous aspiration. Primary hyperparathyroidism should be considered in all patients with cystic neck masses. Parathyroid cysts can often be recognized from the characteristics of the cyst fluid which is usually clear and colorless, contains elevated parathyroid hormone levels and normal or low thyroid hormone levels, and may contain parathyroid cells. Parathyroid cysts may be multiple; all four parathyroid glands should therefore be identified and appropriately removed or hyperparathyroidism may persist.     

Needle aspiration of nonfunctioning parathyroid cysts

Parathyroid cysts, appearing as thyroid masses, have been previously diagnosed at operation or by permanent histologic specimens. With the advent of ultrasound and fine-needle biopsies, these very rare cysts can now be diagnosed by needle aspiration. The pearly clear fluid of a parathyroid cyst contrasts with the sanguineous or even chocolate-brown fluid of a thyroid cyst. The high parathyroid hormone (PTH) level of the fluid confirms the diagnosis, and a blood calcium level determines its function or nonfunction in the patients. Of our seven nonfunctioning parathyroid cysts, the first three were diagnosed by operation and the other four by needle aspirations. The PTH determination ranged from 20,000 to 42,000 pg/mL. We suggest that needle aspiration, rather than operation, be the treatment of choice.     

Cysts of the parathyroid glands. Apropos of 6 cases

Parathyroid cysts are rare lesions. Pathological examination distinguishes the "true" parathyroid cysts (non functional) most often present and cystic degeneration of a parathyroid adenoma (rare) with clinical or biochemical evidence of hyperparathyroidism. With the increased use of ultrasound and fine needle aspiration biopsies, the diagnosis of these cysts can be confirmed by an elevated parathyroid hormone (PTH) assay. The non-functioning parathyroid cysts can be successfully treated by total aspiration of the cyst fluid. Surgical exploration of all parathyroid glands is the treatment of choice for hyperparathyroidism. The different proposed etiologies for parathyroid cysts are discussed.     

Hypercalcemic crisis secondary to a functioning parathyroid cyst

A case of hypercalcemic crisis secondary to a large functioning parathyroid cyst is presented. Because none of the theories about the origin of parathyroid cysts are well substantiated or accepted, these cysts should be referred to simply as parathyroid cysts, functional or nonfunctional.     

Intraparathyroid cyst: a tumour of branchial origin and a possible pitfall for targeted parathyroid surgery

Background: Parathyroid cysts account for 0.5% of parathyroid pathologies. They usually contain sky‐high levels of parathyroid hormone (PTH) but are not necessarily associated with primary hyperparathyroidism (PHPT). Their origin is subject to debate. We provide evidence for a branchial origin and illustrate some potential problems they pose for targeted parathyroid surgery. Methods: The present study is a single institution retrospective study of 1702 parathyroid and 10 021 thyroid operations performed over a period of 12 years (1990?2001). Twenty‐three cases of parathyroid cyst were found: three palpable neck masses, four cases associated with PHPT and 16 incidental findings at the time of thyroid surgery. Intracystic PTH measurements and immunostaining of the lining wall of the cyst were obtained in 16 out of 23 and 18 out of 23 cases, respectively. Results: Intracystic PTH levels were elevated in 15 out of 16 cases (average 3877, range 36 000?23 pg\mL). The wall of the cyst stained positively for epithelial cuboidal cell markers (CK +ve) and negatively for PTH (PTH ?ve) in 18 out of 18 cases. In only one quarter of the cases associated with PHPT was the cyst the hypersecreting gland, nevertheless it contained less than the average PTH level (1440 vs 3877) and did not take up sestamibi. Results were conflicting in the other three cases. Histological studies on the present series suggest a branchial pouch origin. Conclusion: Despite containing high levels of PTH, parathyroid cysts are of branchial origin and when associated with PHPT are rarely responsible for the disease. Targeted parathyroid surgery should not rely only on ultrasound and intraparathyroid PTH measurements.     

Recurrent nerve palsy due to parathyroid cyst

Cysts of the parathyroid gland are uncommon neck masses and difficult to diagnose. They can cause symptoms by endocrinological function or by pressure on surrounding structures. A case of recurrent nerve palsy due to a parathyroid cyst is presented. Aspiration of parathyroid cysts can be diagnostic and therapeutic in some cases.     

Parathyroid cysts: reprot of 2 cases and review of the literature

Although parathyroid cysts are rarely described in the literature, they should be considered in the differential diagnosis of cysts occurring in the anterior compartment of the neck. We report two cases. The presence of elevated parahormone in the clear fluid aspirate is the diagnostic criterion. Parathyroid cysts may be functional, probably resulting from cystic formation of a parathyroid adenoma, or non function with their own epithelial lining, probably arising from remnants of the pharyngeal pouch or Kursteiner's canal. Search for both hypercalcemia and hypophosphoremia are needed. Fine needle aspiration provides the diagnosis and is also the treatment of choice for non-functional parathyroid cysts. Aspiration of functional cysts can reduce the hormone level to normal prior to surgical removal.     

Nonfunctioning parathyroid carcinoma.

Parathyroid carcinoma is a rare clinical entity accounting for only 4 per cent of all cases of parathyroid neoplasia. Nonfunctioning parathyroid carcinoma is even rarer. Previously, virtually all patients with these lesions were treated for a nonspecific neck mass. However, in the present case, a preoperative diagnosis of nonfunctioning parathyroid carcinoma was made based on the technetium pertechnetate/thallium 201 subtraction scan. The authors report on the 14th case of nonfunctioning parathyroid carcinoma, a review of the literature, and guidelines for the preoperative and operative evaluation of neck masses suspected to be parathyroid carcinoma.     

Parathyroid Cyst: Often Mistaken for a Thyroid Cyst

Introduction Parathyroid cysts are rare but clinically significant lesions. They can be functional, mistaken for a thyroid cyst, and/or managed nonoperatively on occasion. Methods We identified seven patients (1 male, 6 females) with the diagnosis of parathyroid cyst from 1998 to 2003. Results Altogether, 33% of the patients had functional cysts. Sestamibi scans were performed in three of the seven patients, including two with functional cysts; none showed focal uptake. In toto, six of the seven cysts (86%) were found in an inferior parathyroid gland. All of the cysts had crystal-clear aspirate. C-terminal parathormone (PTH) levels were obtained from the aspirate from five of the seven (71%) patients. The mean level was 269,736 pg/ml (1970–1,268,074 pg/ml). Surgery was performed in three of the seven (43%) patients. All patients who underwent surgery improved postoperatively based on symptoms and serum levels of calcium and PTH. The four patients (57%) who were treated nonoperatively were subjected to aspiration alone; three (75%) of those patients required multiple aspirations. Conclusions Most parathyroid cysts are nonfunctional and are rarely symptomatic. They are usually located in an inferior gland. If aspirated, most of the cysts reaccumulate fluid. Operative management is usually straightforward and alleviates symptoms and any biochemical abnormalities caused by the cyst. This study was presented as a poster at the meeting of the American Thyroid Association, Vancouver, BC, October 2004     

Giant functioning parathyroid cyst presenting as a retrosternal goitre

Parathyroid cysts are rare and even more rarely cause a neck mass resembling a goitre. Such large parathyroid cysts may involve the mediastinum, growing to a sufficient size to produce symptoms related to obstruction, and if functioning, primary hyperparathyroidism. Parathyroid cysts should be considered in the list of differential diagnoses of anterior neck masses to allow for appropriate preoperative investigation to avoid unnecessary confusion at the time of operation. We report a case where a functioning parathyroid cyst presented as a retrosternal goitre to emphasize the potential pitfalls associated with their diagnosis and management.     

Vitamin D–Independent Therapeutic Effects of Extracellular Calcium in a Mouse Model of Adult‐Onset Secondary Hyperparathyroidism

Cell proliferation and PTH secretion in the parathyroid gland are known to be regulated by vitamin D and extracellular calcium. Here, we examined the vitamin D–independent effects of correction of extracellular calcium in an adult‐onset secondary hyperparathyroidism (sHPT) model, using mice with a nonfunctioning vitamin D receptor (VDR). Wildtype and homozygous VDR mutant mice were kept on a rescue diet (RD) containing 2% calcium (Ca), 1.25% phosphorus (P), and 20% lactose until they were 4 mo or 1 yr of age. Subsequently, 4‐mo‐old mice were switched to a challenge diet (CD) containing the following: 0.5% Ca, 0.4% P, and 0% lactose. After 2 mo on the CD, groups of VDR mutant mice were either fed CD, a normal mouse chow with 0.9% Ca, 0.7% P, and 0% lactose, or the RD for another 3 mo. Feeding the RD protected VDR mutants against sHPT over 1 yr, showing that vitamin D is not essential for long‐term control of the function and proliferation of parathyroid cells. When 4‐mo‐old VDR mutants were switched from the RD to the CD for 2 mo, they developed severe sHPT associated with hypertrophy and hyperplasia of parathyroid glands and profound bone loss. Subsequent feeding of the RD during a 3‐mo therapy phase fully corrected sHPT, reduced chief cell proliferation, and reduced maximum parathyroid gland area by 25% by cell atrophy. There was no evidence of RD‐induced chief cell apoptosis. We conclude that signaling by the calcium‐sensing receptor regulates chief cell function and size in the absence of signaling through the VDR.     

Hormone inactive parathyroid cyst: rare differential diagnosis in the evaluation of cervical cysts

Parathyroid cysts are a very rare disease entity. Hormone activity is uncommon and they usually present without any clinical symptoms. The differential diagnosis of cystic neck masses should nevertheless include parathyroid cysts as surgical therapy can be very effective. We report the case of a 57-year-old patient presenting to our department with a hormone inactive parathyroid cyst. Final diagnosis was achieved eventually after histological examination of the resected specimen, which is the reason for evaluating the current data for preoperative management of this disease entity in this case report.     

Thoracoscopic resection of a giant mediastinal parathyroid cyst

Parathyroid cysts are a rare situation, unusually in the mediastinum. The preoperative diagnosis could be more difficult in some atypical topographies and imaging characteristics in particular in case of huge mediastinal cyst. In the following years traditionally, in case of intrathoracic parathyroid cysts, sternotomy or thoracotomy have been the preferred approaches. We report a case of an older patient with a huge mediastinal parathyroid cyst removed successfully using videothoracoscopy.     

Poor predictability of prenatal ultrasonography for a nonfunctional kidney

We present 2 cases in which the diagnosis of a unilateral nonfunctioning kidney was not anticipated. The first case appeared to be simple, antenatally diagnosed, unilateral hydronephrosis with adequate parenchyma. However, at 3 months postnatally, it was found to be nonfunctional, most likely secondary to early high-grade obstruction. The second case presented prenatally as a left hydronephrotic kidney with parenchymal cysts, and the right kidney showed only mild parenchymal cystic changes. By 6 months, however, the right kidney was nonfunctional. These cases emphasize the need for coordinated prenatal and postnatal care. The sonographic appearance of renal dysplasia is variable (in size, number of cysts, and degree of hydronephrosis), depending on the point at which it is evaluated during the disease course. Subtle signs of dysplasia, such as increased echogenicity, may be the only warning sign of a nonfunctioning kidney, for which one should have a high index of suspicion.