Water-clear parathyroid adenoma: report of two cases and literature review

Relationship between parathyroid adenoma size, weight and histological subtypes with perioperative serum levels

AIMS

This study aims to identify associations between parathyroid adenoma (PTA) characteristics (histology, weight and size) with the change in parathyroid hormone (PTH) and calcium levels.

METHODS

A historical cohort study was conducted on adult patients with solitary PTA removed in the Gold Coast Health Precinct, Australia, between 2017 and 2022.

RESULTS

PTA weight is correlated with the change in day 1 PTH level (r=0.26, p=0.036), the change in day 1 corrected calcium level (r=0.20, p=0.033), and the change in follow-up corrected calcium level (r=0.47, p<0.001). The largest dimension (size) of PTA is also correlated with the change in day 1 PTH (r=0.30, p=0.011) and the change in follow-up corrected calcium level (r=0.40, p<0.001). Adjusted for age and gender, a statistically significant negative correlation was found between day 1 PTH level and adenoma size, resulting in a 0.5% change in size for every percentage change in PTH level (equating to a 5.0% increase in variance explained, p=0.038). Similarly, a negative correlation was identified in day 1 corrected calcium levels and weight, with a 4.7% change in weight for every percentage of change in day 1 corrected calcium level (an increase of 5.6% variance explained, p=0.010). In addition, a negative correlation was identified, where every 3.1% change in size (an increase of 17.4% variance explained, p<0.001) and 7.6% change in weight (an increase of 22.7% variance explained, p<0.001) was seen with every percentage change in follow-up corrected calcium levels. Clear-cell PTA had the most significant percentage fall in day 1 corrected calcium levels compared with other PTA subtypes (p=0.007).

CONCLUSIONS

Preoperative calcium and PTH levels correlate with PTA weight and size. The degree of change in postoperative corrected calcium levels behaved differently in the clear-cell subtype.

Large Water-Clear-Cell Parathyroid Adenoma: A Report of a Rare Case

Water-clear-cell parathyroid adenomas are extremely rare tumors characterized by cells that contain clear, foamy cytoplasm. Here we report a case of a large water-clear-cell parathyroid adenoma in a 70-year-old male. The patient was presented to an outside hospital with severe abdominal pain and supporting CT imaging confirming a small bowel obstruction. Initial laboratory studies revealed hypercalcemia and elevated parathyroid hormone levels. Subsequent ultrasound imaging revealed a 2.7 × 2.1 cm neck mass suspicious for a parathyroid adenoma. A parathyroidectomy was performed, and microscopic evaluation revealed an expansile proliferation of cells with characteristic water-clear cell features. Although rare, water-clear-cell parathyroid adenomas are clinically indistinguishable from more common subtypes and should be considered in the differential diagnosis of an anterior neck mass.

Top 10 Clear Cell Head and Neck Lesions to Contemplate

BACKGROUND

Optically clear cytoplasm may occur in neoplastic and non-neoplastic conditions, either as a characteristic feature of a disease entity or as a morphologic rarity, potentially creating diagnostic dilemmas in various organ systems. In the head and neck, clear cell change can occur in lesions of salivary, odontogenic, thyroid, parathyroid, or sinonasal/skull base origin, as well as in metastases to these regions.

METHODS

This review elaborates the top ten clear cell lesions in the head and neck, emphasizing their distinguishing histologic, immunohistochemical, and molecular attributes, and presents a rational approach to arriving at an accurate classification.

RESULTS

Cytoplasmic pallor or clearing may be caused by accumulations of glycogen, lipid, mucin, mucopolysaccharides, water, foreign material, hydropic organelles, or immature zymogen granules. Overlapping morphologic features may present a diagnostic challenge to the surgical pathologist. Similarity in immunohistochemical profiles, often due to common cell type, as well as rare non-neoplastic mimics, furthers the diagnostic conundrum.

CONCLUSIONS

The top ten lesions reviewed in this article are as follows: (1) clear cell carcinoma (salivary and odontogenic), (2) mucoepidermoid carcinoma, (3) myoepithelial and epithelial-myoepithelial carcinoma, (4) oncocytic salivary gland lesions, (5) squamous cell carcinoma, (6) parathyroid water clear cell adenoma, (7) metastatic renal cell carcinoma (especially in comparison to clear cell thyroid neoplasms), (8) sinonasal renal cell-like adenocarcinoma, (9) chordoma, and (10) rhinoscleroma.

Preoperative, Intraoperative, and Postoperative Parathyroid Pathology: Clinical Pathologic Collaboration for Optimal Patient Management

Parathyroid disease typically presents with parathyroid hyperfunction as result of neoplasia or a consequence of non-neoplastic systemic disease. Given the parathyroid gland is a hormonally active organ with broad physiologic implications and serologically accessible markers for monitoring, the diagnosis of parathyroid disease is predominantly a clinical pathologic correlation. We provide the current pathological correlates of parathyroid disease and discuss preoperative, intraoperative, and postoperative pathology consultative practice for optimal patient care.

Double water-clear cell parathyroid adenoma: a case report and literature review

Water-clear cell parathyroid adenoma is an uncommon cause of primary hyperparathyroidism. Herein, we report an interesting case of a 56-year-old man who presented with weight loss, bone pain, fatigue, and a palpable right neck mass. Laboratory tests indicated hypercalcemia, elevated parathyroid hormone (PTH) levels, and normal thyroid function. Further examinations detected osteoporosis and kidney stones. The ultrasound of neck revealed bilateral extrathyroidal tumors, which were sestamibi-avid. The patient underwent resection of the large right inferior and left inferior parathyroid tumors. Histopathology revealed a double water-clear cell parathyroid adenoma. His serum calcium and PTH levels normalized after surgery. The literature review identified 37 cases of water-clear cell parathyroid adenoma between 1985 and 2021. The median age at diagnosis was 56 years. Classic complications were common, including nephrolithiasis in nine and skeletal presentations in 10 patients. Before surgery, the median calcium and PTH levels were 12.0 mg/dL and 290 pg/mL, respectively. Overall, 89% were localized on ultrasonography, and 60% were positive on scintigraphy. Four patients had double adenomas. The median maximum diameter was 3.8 cm, and the median weight of the resected adenoma was 5.27 g. In summary, water-clear cell parathyroid adenoma has certain unique features. These include larger tumor size, relatively indolent biochemical profile, high prevalence of complications and nonspecific symptoms, an isoechoic appearance on ultrasonography, and reduced scintigraphic sensitivity.

Triple water clear cell parathyroid adenomas: a rare cause of primary hyperparathyroidism

A man in his 70s was referred to the endocrine surgery department after incidental finding of hypercalcaemia during preoperative work-up for abdominal aortic aneurysm repair. The patient reported severe fatigue and malaise with no previous history of nephrolithiasis or osteoporosis. After biochemical confirmation of primary hyperparathyroidism, localisation studies suggested multiple gland disease. Intraoperatively, three enlarged parathyroid adenomas were found and excised. Histopathological and immunohistochemical examination revealed triple water clear cell (WCC) parathyroid adenomas. Adenomas being entirely composed of WCCs are rare. In addition, triple adenomas are so rare that their existence is disputed by some authors. The present paper reports on an extremely rare case of a patient suffering from triple parathyroid adenomas composed entirely of WCCs. To our knowledge, this is the first such reported case in the English language literature.

Histopathological Features of Parathyroid Adenoma and 18F-Choline Uptake in PET/MR of Primary Hyperparathyroidism

BACKGROUND

The aim of this study was to assess the relationship between the histopathological properties of hyperfunctioning parathyroids and parathyroid 18F-choline uptake.

PATIENTS AND METHODS

A total of 31 parathyroid adenomas were retrospectively analyzed in patients with primary hyperparathyroidism and preoperative 18F-choline PET/MR. PET/MR parameters of parathyroid glands (SUVmax and target-to-background ratio in early-phase [EP] and late-phase [LP]), MRI volume, preoperative parathyroid hormone (PTH) serum concentration, and postoperative histopathology (predominant cell type and growth pattern of adenoma cells, location and size of adenoma) were assessed. The relationship of PET/MR parameters, PTH, and histological parameters was determined using linear regression, Spearman correlation and Kruskal-Wallis test.

RESULTS

The median volume of parathyroid adenoma was 421.78 ± 142.46 mm3 (46.39-4412.69). Adenomas were predominantly composed of chief, water-clear, and oncocytic/oxyphilic cells in 27/31, 2/31, and 2/31 cases, respectively. The growth pattern was predominantly solid, follicular, and trabecular in 18/31, 8/31, and 5/31, respectively. The SUVmax was 6.71 ± 3.39 in EP and 6.91 ± 3.97 in LP. Follicular growth pattern had slightly higher EP SUVmax (trabecular: 4.12 ± 0.56; solid: 6.62 ± 3.19; follicular: 8.56 ± 3.96; P = 0.046). Spearman correlation showed strong positive correlation between volume and both EP and LP SUVmax (0.626; P = 0.0001 and 0.576; P = 0.0001, respectively). Linear regression analysis revealed significant correlation between PTH level and EP and LP SUVmax (both P = 0.001); in contrast, no correlation was found between PTH level and both cell type and growth pattern.

CONCLUSIONS

Our findings suggest that 18F-choline uptake of parathyroid adenomas might be associated both with the histological growth pattern and adenoma volume, but not with a specific cell type.

Water clear cell ectopic non-iatrogenic giant parathyroid adenoma in sternohyoid muscle with thyroid nodule and asymptomatic hypercalcemia due to primary hyperparathyroidism: Case report and literature review

Background

Ectopic parathyroid gland is not uncommon, and is associated with primary hyperparathyroidism. Giant parathyroid adenoma (PA) and concurrent presence of enlarged thyroid nodule increases the probability of ectopic location. The combination of a giant PA that is ectopic (within the strap muscle) in the neck is very rare, especially in cases with no previous surgery. The rare histopathological findings of the current case, water clear cell parathyroid adenoma (WCCPA), could explain the patient's presentation, since it has low endocrine function.

Case presentation

A 56-year-old Qatari female on routine visit to primary health care physician for hypertension, was incidentally discovered to be hypercalcemic and was referred to the emergency department of our institution. Neck ultrasound showed a thyroid nodule on the left side, but ^99mTc-sestamibi scintigraphy identified a left PA. FNAC of the thyroid nodule showed that it was a colloid nodule. She underwent left hemithyroidectomy and excision of left PA. Intraoperatively, the PA was giant and in the sternohyoid muscle. Intraoperative monitoring of intact PTH (IOiPTH) confirmed successful excision.

Discussion

Ectopic giant parathyroid adenoma is rare especially with the intramuscular location in sternohyoid muscle in the neck without previous neck surgeries. The presence of thyroid nodule could be a precipitating factor for migration of the PA. Preoperative assessment with the radiological image is crucial for diagnosis but sometimes fail to localized the PA.

Conclusion

Giant asymptomatic PA with long standing low function before hyperfunctioning should raise the suspicion of WCCPA. If diagnosis is confirmed, metastasis from a clear cell renal cell carcinoma should be ruled out.

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We report a unique rare case of non-iatrogenic ectopic giant water clear cell parathyroid adenoma (WCCPA)

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A parathyroid adenoma >3.5 gm, asymptomatic and with low function before hyperfunctioning, should raise suspicion of WCCPA.

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History, examination, ultrasound, sesta-MIBI scintigraphy and immunohistochemical studies are important for diagnosis.

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High preoperative parathyroid hormone and calcium need monitoring in post-operative period to avoid hypocalcemia.

Institutional characterisation of water clear cell parathyroid adenoma: a rare entity often unrecognised by TC-99m-sestamibi scintigraphy

Parathyroid lesions exhibiting a water clear cell morphology are exceedingly rare manifestations in primary hyperparathyroidism (PHPT), and the phenomenon has been reported both for uniglandular (water clear cell adenoma; WCCA) and multiglandular disease (water clear cell hyperplasia; WCCH). In all, only 24 previous descriptions of WCCA exist in the literature. Herein, we present seven cases with water clear cell morphology (6 WCCAs and 1 case of WCCH) in an institutional series of approximately 4000 parathyroid lesions spanning 29 years in a tertiary centre setting. Major histological attributes and clinical parameters associated with this morphological subtype were reviewed, and a literature search was conducted. WCCA and WCHH exhibited an institutional prevalence of 0.15% and 0.025%, respectively. All cases displayed histological hallmarks of water clear cell morphology, with cells exhibiting abundant cytoplasm filled with vacuoles. Atypical findings or unequivocal evidence of invasive behaviour were not observed. The gender distribution was 6:1 (F:M), patients were generally symptomatic with mild hypercalcaemia, and the median age at surgery was 53 years (range 38-78). The preoperative localisation was inconclusive in four of seven, and neck exploration of all four glands was undertaken in five cases. The excised WCCAs exhibited an average weight of 1215 mg, markedly higher than conventional adenomas, and all patients were cured of PHPT following parathyroidectomy. Interestingly, previous reports mirror our observations that these lesions often are large, in relation to their sizes biochemically fairly indolent, and indecisively localised using scintigraphy, providing correlations of possible clinical value when pre-operatively assessing these rare lesions.

An unusual cause of hypercalcemic crisis: Water-clear cell double parathyroid adenoma

Objective

To evaluate the clinical characteristics of a patient operated for water-clear cell adenoma and to discuss these in the light of relevant literature.

Material and Methods

PubMed and Google Scholar were searched to identify articles related to water-clear cell adenoma using the following keywords: parathyroid tissue, parathyroid gland, parathyroid cells, parathyroid adenoma, parathyroid hyperplasia, water-clear-cell, and water clear cell. The search included case reports, review articles, and original articles that had been published between January 1990 and November 2014 without any restrictions on language. All articles that contained information on the study population and treatment related data were identified and retrieved. In addition, an evaluation was of a case of a 47-year-old male patient with PHC who was treated at our clinic was conducted.

Results

A total of 19 patients, including our new case, (age range: 18 to 81 years, mean±SD: 57.47±16.31 years) were included in the analysis. Eleven patients were female. Information about adenoma location was available from studies involving 17 patients and they indicated the following distribution of locations: left inferior (n=10), right superior (n=4). When preoperative imaging methods were examined, a false negative result was given by ultrasonography in 28.5% of patients and only 57.1% were positive on scintigraphy. Concomitant thyroid papillary carcinoma was determined in 1 patient. The mean tissue dimensions were 3.47±1.73 cm (range, 0.8-6.8 cm).

Conclusion

Water-clear cell adenoma, which shows similar clinical characteristics to other parathyroid adenomas, is an uncommon cause of hyperparathyroidism.

Primary hyperparathyroidism caused by enormous unilateral water-clear cell parathyroid hyperplasia

BACKGROUND

Parathyroid water-clear cell hyperplasia (WCCH) and water-clear cell adenoma (WCCA) are rare causes of primary hyperparathyroidism. The frequency of WCCH seems to be less than 1% of all primary hyperplasia.

CASE PRESENTATION

We report a 53-year-old woman with a large unilateral water clear cell parathyroid hyperplasia associated with primary hyperparathyroidism and severe osteoporosis. Ultrasonography showed a 5.4 cm multilobulated hypoechoic well defined mass localized in the lower half of the left thyroid lobe. Technetium sestamibi scanning showed a persistent very large area of increased activity possibly corresponding to a left inferior double parathyroid adenoma. At surgery, two large merged lobulated parathyroid glands were removed from the left superior and inferior aspects of the adjacent thyroid extending to the sub-clavicular area. Histopathology showed polygonal hyperplastic vacuolated cells with abundant water clear cytoplasm. The lesion had lack of capsule or rim of parathyroid tissue and immunohistochemistry was positive for PTH staining. These findings were consistent with diffused water clear cell hyperplasia. After parathyroidectomy, iPTH and calcium levels dropped immediately.

CONCLUSION

The clinical presentation of the patients with water clear cells parathyroid content and hyperparathyroidism is indistinguishable from that of the more common causes of primary hyperparathyroidism of adenoma or hyperplasia and the diagnosis is made only on pathological examination. In conclusion, the distinction of water clear cell hyperplasia from water clear cell adenoma can be challenging in many cases, although clinically significant as far as treatment and follow-up.

Water Clear Cell Adenoma of the Parathyroid Gland: A Forgotten Cause of Primary Hyperparathyroidism

Water clear cell adenoma of the parathyroid gland is a rare neoplasm composed of large clear cells with foamy cytoplasm and mild nuclear pleomorphism, compressing the residual nonneoplastic parathyroid tissue. The differential diagnosis includes a variety of neoplasms with clear cell features. In this article, we provide an overview of the entity with a historical perspective, in order to help pathologists in distinguishing it from other neoplasms in their daily practice.

Intrathyroidal Clear Cell Tumor of Parathyroid Origin with Review of Literature

Water-clear cell adenoma (WCCA) of the parathyroid gland is an exceedingly rare neoplasm. To date, 17 cases have been reported in the literature, with only one of them being intrathyroidal. Here we report a case of a 34-year-old woman who presented for evaluation of a goiter and was found to have a thyroid nodule and abnormal thyroid function tests (TFT). Fine needle aspiration biopsy of the nodule revealed thyroid follicular cells without atypia and subsequent Afirma® Gene Expression Classifier (GEC) testing results were suspicious for malignancy. As a result, the patient underwent a right thyroid lobectomy and isthmusectomy. Histological sections revealed an intrathyroidal nodule consistent with a clear cell neoplasm of parathyroid origin. The histologic appearance together with the immune profile was diagnostic of WCCA, with diffuse positivity for GATA3, focal weak positivity for parathyroid hormone, and negativity for PAX8, thyroglobulin, TTF1, synaptophysin, chromogranin, and S100p. Our study focuses on the clinical presentation, current management strategies, and review of the available literature surrounding this rare diagnosis. The ultimate goal is to help endocrinologists and surgeons establish a foundational treatment plan for intrathyroidal clear cell tumor cases.

Clinicopathological correlates of hyperparathyroidism

Hyperparathyroidism is a common endocrine disorder with potential complications on the skeletal, renal, neurocognitive and cardiovascular systems. While most cases (95%) occur sporadically, about 5% are associated with a hereditary syndrome: multiple endocrine neoplasia syndromes (MEN-1, MEN-2A, MEN-4), hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH-1, FHH-2, FHH-3), familial hypercalciuric hypercalcaemia, neonatal severe hyperparathyroidism and isolated familial hyperparathyroidism. Recently, molecular mechanisms underlying possible tumour suppressor genes (MEN1, CDC73/HRPT2, CDKIs, APC, SFRPs, GSK3β, RASSF1A, HIC1, RIZ1, WT1, CaSR, GNA11, AP2S1) and proto-oncogenes (CCND1/PRAD1, RET, ZFX, CTNNB1, EZH2) have been uncovered in the pathogenesis of hyperparathyroidism. While bi-allelic inactivation of CDC73/HRPT2 seems unique to parathyroid malignancy, aberrant activation of cyclin D1 and Wnt/β-catenin signalling has been reported in benign and malignant parathyroid tumours. Clinicopathological correlates of primary hyperparathyroidism include parathyroid adenoma (80-85%), hyperplasia (10-15%) and carcinoma (<1-5%). Secondary hyperparathyroidism generally presents with diffuse parathyroid hyperplasia, whereas tertiary hyperparathyroidism reflects the emergence of autonomous parathyroid hormone (PTH)-producing neoplasm(s) from secondary parathyroid hyperplasia. Surgical resection of abnormal parathyroid tissue remains the only curative treatment in primary hyperparathyroidism, and parathyroidectomy specimens are frequently encountered in this setting. Clinical and biochemical features, including intraoperative PTH levels, number, weight and size of the affected parathyroid gland(s), are crucial parameters to consider when rendering an accurate diagnosis of parathyroid proliferations. This review provides an update on the expanding knowledge of hyperparathyroidism and highlights the clinicopathological correlations of this prevalent disease.