Functional giant parathyroid cyst with high concentration of CA19-9 in cystic fluid

A Functional Parathyroid Cyst from the Hemorrhagic Degeneration of a Parathyroid Adenoma

A 77-year-old man with a history of hypertension, prostate hyperplasia, and urolithiasis was admitted for acute kidney injury caused by hypercalcemia. Neck ultrasonography showed a large cyst adjacent to the right lower thyroid lobe. Although a ^99mtechnetium sestamibi scan was negative, an extremely high intracystic intact parathyroid hormone level suggested that the cyst had a parathyroid origin and that a functional parathyroid cyst was present. Immunohistochemical staining for the calcium-sensing receptor (CaSR) after right lower parathyroidectomy revealed CaSR-positive cells lining the cyst, indicating that the functional parathyroid cyst had originated from the hemorrhagic degeneration of a parathyroid adenoma.

Diagnostic pitfalls in a cystic ectopic intrathyroidal parathyroid adenoma mimicking a nodular goiter: A care-compliant case report

RATIONALE

Cystic parathyroid adenomas are rare and seldom arise in ectopically located glands which may be found within the carotid sheath, mediastinum, thymus, or thyroid grand. They cannot be detected consistently by any imaging methods. Unusual symptoms may bring about certain pitfalls and difficulties for the diagnosis of primary hyperparathyroidism (PHPT) caused by cystic parathyroid adenomas. Until now, there are no specific guidelines on the management of cystic ectopic intrathyroidal parathyroid adenoma (ETPA).

PATIENT CONCERNS

An 82-year-old male musician presented abrupt thyroid enlargement, hoarseness, and trachea compression when he was playing the clarinet. Thyroid and renal function tests were normal. Serum-free calcium and parathyroid hormone (PTH) were in high concentration. Thyroid ultrasonography (US) detected a giant and cystic nodule within right thyroid lobe, which is the very image of cystic nodular goiter. Parathyroid US was negative. The cystic nodule had a decreasing radioactive uptake of Technetium-99m-methoxyisobutylisonitrile (Tc-MIBI). At patient's request, the invasive fine-needle aspiration (FNA) was not conducted.

DIAGNOSES

The patient was initially diagnosed as cystic nodular goiter and inconclusive PHPT.

INTERVENTIONS

Enucleation of solitary cystic intrathyroidal nodule was conducted.

OUTCOMES

The cystic nodule strongly resembled a nodular goiter grossly, but it was proved cystic ETPA by histopathology. Postoperative follow-ups found that serum-free calcium and PTH decreased sharply into normal range, and hoarseness and trachea displacement were obviously improved.

LESSONS

The diagnosis of cystic ETPA is easily overlooked for its rarity. Diagnostic pitfalls, including atypical symptoms, inconclusive imaging manifestation, and unidentified gross specimen, are highlighted. They make the diagnosis of PHPT caused by cystic ETPA challenging. Patients would rather choose surgical excision directly than invasive FNA. Acute hemorrhage of the preexisting ETPA may account for the cystic degeneration.

Parathyroid cysts: A review of 359 patients reported in the international literature

BACKGROUND

Parathyroid cysts are lesions that represent 1-5% of neck masses. They are subdivided into two categories: functioning and non-functioning.The aim of the present review is to give a detailed account of all reported cases of parathyroid cysts in the literature and to analyze statistically the available data.

METHODS

A bibliographic research was performed from 1905 until 2016. A database with the patients' characteristics was made and analyzed statistically.

RESULTS

A total of 218 articles were found, reporting 359 cases of cysts. Mean age of patients was 49.24 y/o and the male/female ratio was 1:1.85. The most common locations were left thyroid lobe (113/358 patients, 31.6%), and superior mediastinum (69/358 patients, 19.3%), while the most common symptoms were neck mass (148/355 patients, 41.7%), compressive symptoms (73/355 patients, 206%) and hyperparathyroidism (62/355 patients, 17.5%). Non-functioning cysts were more frequent (220/357 patients, 61.6%). Regarding dimensions, mean diameter was 4.88 cm. Ultrasound and FNA are used for their diagnosis, while cystic fluid analysis may help the differential diagnosis. Recurrences were mentioned in 27/97 patients (27.8%) with available data. No deaths due to parathyroid cysts were mentioned in the literature.

CONCLUSION

Parathyroid cysts should be taken into consideration in case of parathyroid dysfunction or asymptomatic neck mass. The surgeon's careful manipulations on the cyst are crucial for a definitive treatment.

The Clinical Features of Cystic Parathyroid Adenoma in Chinese Population: A Single-Center Experience

OBJECTIVE

Cystic parathyroid adenoma is a rare cause of primary hyperparathyroidism, but its preoperative diagnosis and management remain inconclusive.

METHOD

We retrospectively identified patients with cystic parathyroid adenomas who underwent surgery at Peking Union Medical College Hospital.

RESULTS

Patients with cystic parathyroid adenomas had higher serum intact parathyroid hormone and calcium levels, larger maximum tumor diameter, and lower serum inorganic phosphorus level than did those with solid adenomas. Patients with cystic adenomas were predominantly male, and hypercalcemic crisis and atypical adenomas were common. The accuracy of preoperative localization methodologies was lower in patients with cystic adenomas than in patients with solid adenomas. US-guided fine-needle aspiration was performed in 11 patients. In all patients, the iPTH level in cystic fluid was much higher than that in serum. No sign of recurrence was observed after a median follow-up of 39 months.

CONCLUSIONS

Cystic parathyroid adenomas may not be as rare as previously reported. FNA may be a safe and feasible localization methodology for patients with inconclusive preoperative localization methodologies. Close follow-up is necessary for patients with cystic parathyroid adenomas, which account for a substantial proportion of atypical adenoma cases.

Cystic parathyroid glands in MEN1: A rare entity?

Approximately 300 cases of sporadic parathyroid cyst (PCs) have been reported to date. Only two cases have been described in MEN1 so far. Detection by imaging could be challenging, especially in multiglandular primary hyperparathyroidism (HPT) and clinical outcome could be different. During the period 1990-2014, 71 MEN1 patients were operated for primary hyperparathyroidism in our centre. We report three cases of PCs in MEN1 patients affected by HPT, who underwent a total or subtotal parathyroidectomy with transcervical thymectomy. In our series, all three patients had an unsatisfactory postoperative course, at variance with the high percentage (over 90 %) of long-term success in MEN1 patients operated at our centre. One patient affected by cystic degeneration of all the four parathyroid glands reported persistent hypoparathyroidism, despite autografts of parathyroid tissue. For the other two cases, surgery failed to cure hyperparathyroidism, perhaps because of the presence of undetected ectopic parathyroid tissue. In the context of a multiglandular disease such as MEN1 syndrome, PCs seem rare but our experience shows about a 4 % incidence. Furthermore their presence, even in expert hands, could affect the preoperative identification of the parathyroid glands due to the difficult differential diagnosis between PC and other cystic lesions of the neck, and intraoperative detection of the glands as well as the postoperative outcome.

Functional parathyroid cyst in a patient with systemic lupus erythematosus: a case report

Functional parathyroid cysts are a rare cause of primary hyperparathyroidism and are often mistaken for thyroid cysts. Systemic lupus erythematosus (SLE) is also a very rare cause of hypercalcemia. We report the case of a 62-year-old woman, who was diagnosed with SLE 30 years ago, presenting with clinical and biochemical features of primary hyperparathyroidism. Laboratory investigation revealed increased serum calcium and parathyroid hormone (PTH) levels; neck ultrasonography (USG) revealed 40×34×26 mm cystic mass in the left lobe of thyroid gland. PTH level in the cysts was >2500 pg/ml, determined by USG-guided fine-needle aspiration (FNA). In this case, no evidence for potential pathogenic association between parathyroid cyst and SLE was uncovered. However, the recognition of this association is very important because the therapeutical strategy is completely different. Operative management is usually straightforward and alleviates symptoms and any biochemical abnormalities caused by the cyst.

Persistent high level of urinary tumor marker carbohydrate antigen 19-9 in prenatally diagnosed dysplastic kidney

Tumor marker carbohydrate antigen 19-9 (CA 19-9) level has gained clinical significance in gastrointestinal malignancies and in various solid and cystic diseases. Dysplastic kidney is a congenital abnormality resulting from atresia of the ureteral bud during the embryogenesis which can be unilateral or bilateral. We report unilateral dysplastic kidney with extremely large cyst diagnosed by routine ultrasonography in the 32nd week of gestational age with high levels of CA 19-9 in cystic and amniotic fluid, as well as persistent high urinary levels of this tumor marker during the 1-year follow-up. Persistent high urinary CA 19-9 level even after cyst aspiration may be attributable to remained function of dysplastic kidney due to remained epithelial lining.

Hyperparathyroidism caused by a functional parathyroid cyst

A 67-year-old Japanese woman was admitted to our hospital for malaise and loss of appetite. Relevant biochemical examinations showed definite hypercalcaemia and elevated serum levels of intact parathyroid hormone (PTH). We performed thyroid ultrasonography and CT of the neck, which revealed a cystic lesion in the right lower lobe of the thyroid glands. Ultrasound-guided fine-needle aspiration was performed, and PTH level of the cystic fluid was markedly elevated. Technetium-99m-hexakis 2-methoxyisobutyi isonitrile sesta scintigraphy showed intense ring-shaped accumulation of radioactivity in the wall of the cyst. The patient underwent a right lobectomy to resect the cystic parathyroid adenoma. After surgery, her serum calcium and PTH level returned to normal ranges.

A large functioning parathyroid cyst in a patient with multiple endocrine neoplasia type 1

A 62-year-old woman presented with a mass on the left side of the neck. Biochemical testing revealed primary hyperparathyroidism. Further, a prolactinoma was detected, and the patient's son and daughter also had primary hyperparathyroidism, indicating that the patient had multiple endocrine neoplasia type 1 (MEN1). Neck ultrasonography revealed several cystic nodules (≤ 30 mm) that appeared to be adenomatous. After parathyroidectomy with autotransplantation, the largest cystic mass, in the left lower thyroid lobe, was pathologically diagnosed as a functioning parathyroid cyst, and all laboratory data returned to normal. On genetic analysis of blood, we found a novel single base insertion (duplication) in exon 10 codon 552 of the MEN1 gene (c1659dupT) that creates an early stop codon. This is the first case report of a parathyroid cyst resulting from parathyroid hyperplasia in a MEN1 patient.

Cystic parathyroid adenoma within a multinodular goiter: a rare cause of primary hyperparathyroidism

Parathyroid cysts are uncommon lesions that do not have a specific sonographic appearance. We report a rare case of a functionally active cystic parathyroid adenoma as a cause of primary hyperparathyroidism and discuss the difficulties associated with the diagnosis. In this case, the association with a multinodular goiter made preoperative differentiation from thyroid cysts difficult. Demonstration of a high intact parathyroid hormone level in the aspirated cyst fluid was critical for the correct diagnosis.