Worrisome histologic alterations following fine-needle aspiration of the parathyroid

Fine needle aspiration biopsy of parathyroid; is it meaningful? A cytologic study of 81 cases with histological and clinical correlations

BACKGROUND

Recognizing the parathyroid gland and distinguishing the parathyroid from thyroid lesions in fine needle aspiration (FNA) is challenging. This study aimed to identify cytomorphologic features suggestive of parathyroid origin and to assess the utility of cytopathology in conjunction with ancillary tests in the identification of parathyroid glands.

MATERIALS AND METHODS

Ultrasound (US) guided FNA of parathyroid gland and lesions in 81 patients were reviewed concerning clinical history and correlated to histopathologic findings in available cases. FNA smears were evaluated for cellularity, architectural patterns, cellular and nuclear features, and background of the smears. In 78 cases, FNA was supplemented by a measurement of parathormone (PTH) levels in the needle washout fluid (FNA-PTH assay) and/or GATA3/PTH/chromogranin-A immunostainings.

RESULTS

Sixty-four cases were diagnosed cytologically as parathyroid lesions in conjunction with FNA-PTH assay and/or immunocytochemical examinations. In an additional nine cases, a diagnosis of parathyroid lesions was rendered after repeated FNA with FNA-PTH assay. The histolopathologic diagnosis of surgically excised cases (n = 75) included parathyroid adenoma (60 cases), atypical parathyroid adenoma (4 cases), parathyroid hyperplasia (10 cases), and parathyroid carcinoma (1 case). Major cytological findings of parathyroid tissue included high cellularity, scattered naked nuclei, cribriform and three-dimensional clusters, stippled chromatin, and oxyphilic cytoplasm while papillary pattern or colloid-like material was identified in three cases respectively. No nuclear grooves or inclusions were seen in any case.

CONCLUSIONS

High cellularity scattered naked nuclei, cribriform and three-dimensional patterns, stippled chromatin and oxyphilic cytoplasm are cytomorphologic features that favour parathyroid origin. A combination of these features with FNA-PTH assay and/or GATA3, PTH, and chromogranin-A immunostainings on cytologic specimens aid in the identification of parathyroid glands and the distinguishing of parathyroid from thyroid lesions.

Parathyroid fine needle aspiration with PTH washout: Can it lead to parathyroid cell seeding in primary hyperparathyroidism?

Although parathyroid fine-needle aspiration (P-FNA) with parathyroid hormone (PTH) washout is effective in detecting preoperative parathyroid lesions, it also presents risks such as fibrosis, hematoma, and, in rare cases, tumor seeding. This study aimed to investigate whether P-FNA with PTH washout leads to the seeding of parathyroid cells along the path of the needle. A retrospective analysis was conducted on patients undergoing minimally invasive parathyroidectomy guided by preoperative PTH washout. Permanent pathology reports, imaging data, and postoperative serum parathyroid hormone and calcium levels were assessed to determine the effectiveness and safety of the procedure. Complications following P-FNA with PTH washout were also reviewed using data from the patient registration system of Bulent Ecevit University. The procedure accurately localized parathyroid adenomas in 87 patients who underwent ultrasound-guided parathyroidectomy following preoperative P-FNA and PTH washout. Postoperatively, 75 patients showed normal parathyroid hormone and calcium levels. Two patients required secondary surgery for contralateral adenomas. Critically, there was no evidence of P-FNA with PTH washout-induced parathyromatosis or seeding during the follow-up. Effective adenoma localization is crucial for successful minimally invasive surgery of hyperparathyroidism. Our study indicates that combining preoperative P-FNAB with PTH washout and imaging enhances adenoma detection, especially when intraoperative PTH measurements are not available, thus improving surgical outcomes. Notably, we found no evidence of cell implantation after P-FNA, suggesting the safety and efficacy of this method for preventing parathyroid cell seeding.

Remission of primary hyperparathyroidism after fine needle aspiration of a parathyroid nodule mistaken for a thyroid nodule

Primary hyperparathyroidism (PHPT) is an endocrine disorder characterized by hypercalcaemia and elevated or inappropriately normal concentrations of parathyroid hormone. Remission of PHPT caused by infarction or hemorrhage of a parathyroid adenoma rarely occurs, either spontaneously or induced, not always leading to a definitive cure. We report a case of 72-year-old women with primary hyperparathyroidism who underwent fine-needle aspiration cytology (FNAC) of a parathyroid adenoma mistaken for a thyroid nodule followed by normalization of parathyroid hormone (PTH) and serum calcium levels. Parathyroid origin was confirmed by immunohistochemistry. PTH levels began to rise at 4 months after FNAC demonstrating recurrence of the PHPT. This report shows that FNAC induced hemorrhage may cause remission of PHPT. Nevertheless, patient´s levels of PTH and serum calcium should be monitored, as remission may only be transitory.

Advances and Updates in Parathyroid Pathology

Hyperparathyroidism is a common endocrine disorder characterized by elevated levels of parathyroid hormone and hypercalcemia and is divided into 3 types: primary, secondary, and tertiary. Distinction between these types is accomplished by correlation of clinical, radiologic, and laboratory findings with pathologic features. Primary hyperparathyroidism occurs sporadically in 85% of cases with the remaining cases associated with multiple familial syndromes. The pathologic manifestations of primary hyperparathyroidism include parathyroid adenoma, parathyroid hyperplasia, and parathyroid carcinoma. Recent advances in the understanding of the pathogenesis of parathyroid disease has helped to refine the diagnosis and classification of parathyroid lesions. The identification of multiple clonal proliferations in traditional multiglandular parathyroid hyperplasia has led to the adoption by the World Health Organization (WHO) of the alternate term of primary hyperparathyroidism-related multiglandular parathyroid disease. Additional nomenclature changes include the adoption of the term atypical parathyroid tumor in lieu of atypical parathyroid adenoma to reflect the uncertain malignant potential of these neoplasms. Clinical and morphologic features characteristic of familial disease have been described that can help the practicing pathologist identify underlying familial disease and provide appropriate management. Use of ancillary immunohistochemistry and molecular studies can be helpful in classifying parathyroid neoplasms. Parafibromin has proven useful as a diagnostic and prognostic marker in atypical parathyroid tumors and parathyroid carcinomas. This review provides an update on the diagnosis and classification of parathyroid lesions considering the recent advances in the understanding of the molecular and clinical features of parathyroid disease and highlights the use of ancillary studies (immunohistochemical, and molecular) to refine the diagnosis of parathyroid lesions.

Diagnosis of parathyroid incidentaloma detected on thyroid ultrasonography: the role of fine-needle aspiration cytology and washout parathyroid hormone measurements

PURPOSE

The aim of this study was to assess the diagnostic role of fine-needle aspiration cytology (FNAC) and analyze factors associated with false-negative FNAC results in patients with parathyroid incidentaloma who were referred for ultrasonography (US)-guided fine-needle aspiration (FNA) of thyroid nodules.

METHODS

In this study, 121 patients with suspected parathyroid lesions were enrolled. The patients underwent US-guided FNAC with measurements of washout parathyroid hormone (PTH) between January 2015 and May 2020. The diagnostic performance of FNAC for the diagnosis of parathyroid lesions was assessed using surgical results and elevated washout PTH as a reference standard. The clinical and radiologic features associated with false-negative results on FNAC for the diagnosis of parathyroid lesions were evaluated.

RESULTS

Among the 121 nodules assessed, 38 were parathyroid lesions (31.4%), and 83 were non-parathyroid lesions (68.6%). The diagnostic performance of FNAC for parathyroid incidentaloma showed a sensitivity of 31.6% (12/38), specificity of 100% (83/83), positive predictive values of 100% (12/12), negative predictive values of 76.1% (83/109), and accuracy of 78.5% (95/121). The FNAC results of non-parathyroid lesions included thyroid nodules, lymph nodes, neurogenic tumors, and fat tissue. True-positive results on FNAC were significantly associated with performing FNA twice (58.3% vs. 23.1%, P=0.043).

CONCLUSION

Considering the low sensitivity of FNAC, measuring washout PTH in addition to FNAC may help accurately diagnose parathyroid incidentaloma on thyroid US. Further, the falsenegative rate for FNAC can be reduced by obtaining two or more FNA samples.

Update on Preoperative Parathyroid Localization in Primary Hyperparathyroidism

Parathyroidectomy is the treatment of choice for primary hyperparathyroidism when the clinical criteria are met. Although bilateral neck exploration is traditionally the standard method for surgery, minimally invasive parathyroidectomy (MIP), or focused parathyroidectomy, has been widely accepted with comparable curative outcomes. For successful MIP, accurate preoperative localization of parathyroid lesions is essential. However, no consensus exists on the optimal approach for localization. Currently, ultrasonography and technetium-99m-sestamibi-single photon emission computed tomography/computed tomography are widely accepted in most cases. However, exact localization cannot always be achieved, especially in cases with multiglandular disease, ectopic glands, recurrent disease, and normocalcemic primary hyperparathyroidism. Therefore, new modalities for preoperative localization have been developed and evaluated. Positron emission tomography/computed tomography and parathyroid venous sampling have demonstrated improvements in sensitivity and accuracy. Both anatomical and functional information can be obtained by combining these methods. As each approach has its advantages and disadvantages, the localization study should be deliberately chosen based on each patient's clinical profile, costs, radiation exposure, and the availability of experienced experts. In this review, we summarize various methods for the localization of hyperfunctioning parathyroid tissues in primary hyperparathyroidism.

Overview of the 2022 WHO Classification of Parathyroid Tumors

The 2022 WHO classification reflects increases in the knowledge of the underlying pathogenesis of parathyroid disease. In addition to the classic characteristic features of parathyroid neoplasms, subtleties in histologic features which may indicate an underlying genetic abnormality reflect increased understanding of the clinical manifestations, histologic, and genetic correlation in parathyroid disease. The importance of underlying genetic aberrancies is emphasized due to their significance to the care of the patient. Traditionally, the term "parathyroid hyperplasia" has been applied to multiglandular parathyroid disease; however, the concept of hyperplasia is generally no longer supported in the context of primary hyperparathyroidism since affected glands are usually composed of multiple "clonal" neoplastic proliferations. In light of these findings and management implications for patient care, the 2022 WHO classification endorses primary hyperparathyroidism-related multiglandular parathyroid disease (multiglandular multiple parathyroid adenomas) as a germline susceptibility-driven multiglandular parathyroid neoplasia. From such a perspective, pathologists can provide additional value to genetic triaging by recognizing morphological and immunohistochemical harbingers of MEN1, CDKN1B, MAX, and CDC73-related manifestations. In the current WHO classification, the term "parathyroid hyperplasia" is now used primarily in the setting of secondary hyperplasia which is most often caused by chronic renal failure. In addition to expansion in the histological features, including those that may be suggestive of an underlying genetic abnormality, there are additional nomenclature changes in the 2022 WHO classification reflecting increased understanding of the underlying pathogenesis of parathyroid disease. The new classification no longer endorses the use of "atypical parathyroid adenoma". This entity is now being replaced with the term of "atypical parathyroid tumor" to reflect a parathyroid neoplasm of uncertain malignant potential. The differential diagnoses of atypical parathyroid tumor are discussed along with the details of worrisome clinical and laboratory findings, and also features that define atypical histological and immunohistochemical findings to qualify for this diagnosis. The histological definition of parathyroid carcinoma still requires one of the following findings: (i) angioinvasion (vascular invasion) characterized by tumor invading through a vessel wall and associated thrombus, or intravascular tumor cells admixed with thrombus, (ii) lymphatic invasion, (iii) perineural (intraneural) invasion, (iv) local malignant invasion into adjacent anatomic structures, or (v) histologically/cytologically documented metastatic disease. In parathyroid carcinomas, the documentation of mitotic activity (e.g., mitoses per 10mm²) and Ki67 labeling index is recommended. Furthermore, the importance of complete submission of parathyroidectomy specimens for microscopic examination, and the crucial role of multiple levels along with ancillary biomarkers have expanded the diagnostic workup of atypical parathyroid tumors and parathyroid carcinoma to ensure accurate characterization of parathyroid neoplasms. The concept of parafibromin deficiency has been expanded upon and term "parafibromin deficient parathyroid neoplasm" is applied to a parathyroid neoplasm showing complete absence of nuclear parafibromin immunoreactivity. Nucleolar loss is considered as abnormal finding that requires further molecular testing to confirm its biological significance. The 2022 WHO classification emphasizes the role of molecular immunohistochemistry in parathyroid disease. By adopting a question-answer framework, this review highlights advances in knowledge of histological features, ancillary studies, and associated genetic findings that increase the understanding of the underlying pathogenesis of parathyroid disease that are now reflected in the updated classification and new entities in the 2022 WHO classification.

A novel parotid carcinoma with a prominent ghost cell population: a masquerading tumor or "salivary ghost cell carcinoma"?

Ghost cell is one of several unique cellular morphologies associated with aberrant keratinization. We encountered a novel parotid tumor containing numerous ghost cells and herein describe its histological features and discuss diagnostic problems. The patient was a 90-year-old Japanese male, who complained of swelling of the left parotid area for four months. Positron emission tomography indicated no cervical lymph node metastasis or distant metastasis. The tumor was successfully resected with no signs of recurrence or metastasis for six months after surgery. Histologically, the tumor was mainly composed of squamous cells forming irregularly shaped nests with a mixture of pleomorphic giant or multinucleated cells and bland basaloid cell. Keratinized areas were occupied by a prominent ghost cell population. Immunohistochemically, CK5/6 and CK19 were widely positive as well as AE1/AE3, p40 and p63. Nuclear expression of β-catenin was also observed. The present case can be regarded as a particular form of squamous cell carcinoma and is believed to contain a large number of ghost cells resulting from an unclear mechanism. However, it seems difficult to consider such tumors as a clinicopathologically independent entity at present. Applying a term such as "salivary ghost cell carcinoma" would be premature.

The Value of Preoperative and Intraoperative Ultrasound in the Localization of Intrathyroidal Parathyroid Adenomas

AIM

Intrathyroidal parathyroid adenoma (IPA) is rare and may easily be mistaken for thyroid nodule in ultrasonography. The aim of this study was to investigate the characteristic features of IPA and explore the value of preoperative and intraoperative ultrasound in the diagnosis and localization of IPA.

METHODS

13 of 216 patients who were found to have intrathyroidal parathyroid lesions underwent parathyroidectomy in our hospital because of PHPT. According to the relationship between parathyroid adenoma and thyroid gland, parathyroid adenoma was divided into extra-thyroid type or intra-thyroid type (partial or complete) and the results were compared with surgical and histopathological reports as gold standard. The sonographic features of intrathyroidal parathyroid lesions were analyzed retrospectively.

RESULTS

A total of 12 intrathyroidal lesions showed profoundly hypoechoic solid nodules with well-defined border, abundant blood flow and polar feeding vessels originating from the superior or inferior thyroid artery (92.3%, 12/13). These nodules were finally confirmed as IPA (or IPAC) after surgery. Polar feeding vessel was not detected in one case of parathyroid hyperplasia confirmed by pathology (7.7%, 1/13). 12 cases were diagnosed and localized on ultrasonography before operation and 10 cases were localized on Tc-99m MIBI SPECT/CT.

CONCLUSIONS

The color Doppler ultrasound findings of IPA were confirmed as profoundly hypoechoic nodules with clear boundary and abundant internal blood flow. The presence of polar feeding vessels which originate from thyroid artery were identified as characteristic features of US for IPA. Preoperative and intraoperative ultrasound could be helpful in the localization and treatment of intrathyroidal parathyroid diseases.

Remission of Primary Hyperparathyroidism Following Fine-Needle Aspiration Biopsy: A Case Report and Review of the Literature

Background

Spontaneous or fine-needle aspiration biopsy (FNAB)-induced remission of primary hyperparathyroidism (PHPT) is an extremely rare and generally transient phenomenon.

Methods

A 40-year-old woman with a history of recurrent kidney stones was diagnosed with PHPT (serum calcium, 14.2 mg/dL; parathyroid hormone [PTH], 380 pg/mL). Ultrasonography and scintigraphy findings were consistent with a left enlarged parathyroid. Ultrasound-guided-FNAB cytology of the lesion did not confirm a parathyroid nature. However, levels of PTH within the needle-washing fluid were elevated.

Results

After few days, there was evidence of biochemical remission of the hypercalcemia (calcium, 8.1 mg/dL), and at subsequent follow-up visits, the enlarged parathyroid showed progressive shrinkage with eucalcemia and normalized PTH levels throughout 12 months of follow-up.

Conclusions

Rarely, remission of PHPT may occur after ultrasound-guided-FNAB performed on a hyperfunctioning parathyroid lesion.

Histological alterations following fine-needle aspiration for parathyroid adenoma: Incidence and diagnostic problems

This study aimed to clarify the histological alterations following fine-needle aspiration for parathyroid adenoma and discuss the occurrence of diagnostic problems. Among the 392 patients with parathyroid adenoma who underwent resection, fine-needle aspiration was performed for 21 (5.1%) parathyroid adenoma nodules. Histological findings that were significantly more frequent in cases that underwent fine-needle aspiration were considered histological alterations following fine-needle aspiration for parathyroid adenoma, including the following six findings: thick fibrous capsule (71.4%), multilayered fibrous capsules (14.3%), capsular pseudo-invasion (42.9%), fibrous bands (57.1%), hemosiderin deposition (14.3%), and tumor implantation (14.3%). Eighteen parathyroid adenoma nodules (85.7%) exhibited one or more of the six findings. Tumor cells and adipocytes entrapped within the thick fibrous capsule were occasionally observed. The fibrous bands were frequently connected to the thick fibrous capsule. The number of passes, duration between fine-needle aspiration and resection, tumor size, and purpose of fine-needle aspiration were not related to the incidence of histological findings. Because of the histological alterations following fine-needle aspiration for parathyroid adenoma that can be easily mistaken for signs of atypical adenoma or parathyroid carcinoma, we recommend that the six findings be excluded from pathological findings indicating atypical adenoma or parathyroid carcinoma in patients with preoperative fine-needle aspiration.

Case of medullary thyroid carcinoma with desmoid-type fibromatosis

A 36-year-old man was admitted to hospital for a right thyroid nodule incidentally discovered on a chest computed tomography scan for a rib fracture. He had no history of radiation to the head and neck, no known family history of endocrine disease, and no medical or surgical history. A 17 × 10 mm, well-demarcated, multinodular, whitish nodule with neither necrosis nor hemorrhage was found in the right thyroid. Microscopically, the tumor consisted of epithelial cell nests with oval, plasmacytoid or polygonal cells with speckled chromatin, inconspicuous nucleoli and granular cytoplasm. The surrounding stroma showed amyloid deposition and prominent spindle cell proliferation with myxoid substance. Epithelial cell nests showed an immunoreactive pattern for typical medullary thyroid carcinoma (MTC), and the spindle cell stroma showed nuclear expression of beta-catenin. This may be the first report on histopathologic findings of MTC with desmoid-type fibromatosis. Further studies are necessary to discover the clinicopathologic characteristics and pathogenesis of this rare type of tumor.

Atypical presentation of oncocytic parathyroid adenoma masquerading as metastatic carcinoma

Parathyroid carcinoma is the rarest endocrine malignancy. Definitive diagnosis is challenging as it is difficult to distinguish malignant from benign disease. A 71-year-old man presented with weight loss and hypercalcaemia. CT scans revealed multiple lung nodules and lytic bone lesions that were consistent with metastatic dissemination. Technetium-99m-sestamibi-single-photon emission computed tomography scan showed an abnormal uptake in the right thyroid lobe. Fine-needle aspiration (FNA) was performed on three occasions. The patient underwent parathyroidectomy with ipsilateral hemithyroidectomy without postoperative complications. Microscopic examination showed a parathyroid neoplasm with fibrosis and intravascular tumour on a background of unremarkable thyroid parenchyma. This resulted in an initial impression of parathyroid carcinoma. Further review by two independent pathologists provided a final diagnosis of oncocytic parathyroid adenoma. This case highlights the subjectivity and interobserver variation with endocrine histological examination. FNA can induce changes that mimic parathyroid carcinoma on histology. An index of suspicion for benign parathyroid adenomas should be maintained.

Parafibromin immunostainings of parathyroid tumors in clinical routine: a near-decade experience from a tertiary center

The cell division cycle 73 gene is mutated in familial and sporadic forms of primary hyperparathyroidism, and the corresponding protein product parafibromin has been proposed as an adjunct immunohistochemical marker for the identification of cell division cycle 73 mutations and parathyroid carcinoma. Here, we present data from our experiences using parafibromin immunohistochemistry in parathyroid tumors since the marker was implemented in clinical routine in 2010. A total of 2019 parathyroid adenomas, atypical adenomas, and carcinomas were diagnosed in our department, and parafibromin staining was ordered for 297 cases with an initial suspicion of malignant potential to avoid excessive numbers of false positives. The most common inclusion criteria for immunohistochemistry were marked tumor weight (146 cases) and/or fibrosis (77 cases) and/or marked pleomorphism (58 cases). In total, 238 cases were informatively stained, and partial or complete loss of nuclear parafibromin immunoreactivity was noted in 40 cases; 10 out of 182 adenomas (5%), 27 out of 46 atypical adenomas (59%), and 7 out of 10 carcinomas (70%), with positive and negative predictive values of 85 and 90%, respectively for the detection of atypical adenomas/carcinomas versus adenomas, and 18 and 98%, respectively for carcinomas versus atypical adenomas/adenomas. Male patients with high-proliferative tumors were overrepresented among cases with aberrant parafibromin immunohistochemistry, and carcinomas more frequently harbored parafibromin aberrancies than atypical adenomas and adenomas (p < 0.001). We conclude that parafibromin immunohistochemistry is a useful marker in the clinical routine when applied on a pre-selected material of cases, with positive immunoreactivity as a confident rule out marker of malignancy.

[Clinical and morphological characteristics of parathyroid carcinoma]

Parathyroid carcinoma (PTC) is a rare malignant tumor with the clinical manifestation of hyperparathyroidism, reliable morphological signs of invasive growth, and poor clinical prognosis. The differential diagnosis of PTC due to the rarity of this pathology, not always explicit morphological criteria, and the lack of a certain immunohistochemical panel is complex and needs further clarification. The paper summarizes an update on the clinical and morphological characteristics of PTC.

The diagnostic value of parathyroid hormone washout in primary hyperparathyroidism patients with negative or equivocal 99 m Tc-MIBI results

BACKGROUND AND OBJECTIVES

The accurate identification of hyper functioning parathyroid gland is needed for definitive surgical treatment in primary hyperparathyroidism. Ultrasonography and 99mTechnetium sestamibi scintigraphy are the two most used methods with varying sensitivities. This study aimed to assess the value of parathyroid hormone (PTH) assay in preoperative ultrasound guided fine needle aspiration (FNA)-PTH washout fluid to verify the correct localisation of lesions with negative or inconclusive scintigraphy results.

METHODS

We evaluated data of 28 lesions in 21 patients who underwent US-guided parathyroid fine-needle aspiration (FNA) with PTH washout, retrospectively. The PTH washout results and the reports of parathyroid surgery and imaging studies were reviewed.

RESULTS

Of operated 28 lesions 23 had positive and 5 had negative washout results. The median FNA-PTH washout was 2315.5 pg/ ml (min-max: 12.3-6978 pg/ ml). The calculated sensitivity of FNA-PTH washout was 85.7% and the specifity was 28.6%. The positive and negative predictive values were 78.3% and 40.0%, respectively.

CONCLUSIONS

FNA-PTH can be used to establish the nature of the lesion, discriminate parathyroid gland from thyroid lesions or cervical lymph nodes, improving the surgical outcomes. It can be used to localise parathyroid lesions preoperatively when negative or discordant ultrasound and scintigraphy findings are obtained.

Two cases synchronous atypical parathyroid adenomas and papillary thyroid carcinoma

Наиболее часто первичный гиперпаратиреоз (ПГПТ) в сочетании с раком (как правило, медуллярным) щитовидной железы (ЩЖ) встречается при синдромах множественных эндокринных неоплазий. Сочетание немедуллярных карцином ЩЖ и ПГПТ отмечается у 3% пациентов. Доля папиллярного рака (ПР) ЩЖ достигает 87% от всех ее злокачественных опухолей. Атипическая аденома (АА) околощитовидной железы (ОЩЖ) – это новообразование, в котором отсутствуют достоверные признаки инвазивного роста, но есть морфологические критерии, подозрительные в отношении их злокачественного потенциала. Распространенность АА ОЩЖ как причины ПГПТ составляет около 0,5–4%. АА ОЩЖ относятся к опухолям неопределенного злокачественного потенциала. Клиническое значение и отдаленные результаты, а также объем оперативного вмешательства и продолжительность наблюдения за пациентами с АА ОЩЖ из-за редкости опухоли и отсутствия стандартов диагностики данной патологии не определены. В настоящей статье авторы сообщают о двух случаях сочетания АА ОЩЖ и ПР ЩЖ у 63-летней женщины и 57-летнего мужчины. У одного из пациентов, в отличие от второго, были классические симптомы ПГПТ, в том числе тяжелая остеодистрофия и нефропатия. Предоперационный уровень кальция составил 3,48 и 4,1 (2,12–2,6) мкмоль/л, паратиреоидного гормона – 1300 и 1533 (15–65) пг/мл соответственно. В обоих случаях ультразвуковое исследование ЩЖ не выявило достоверно злокачественных новообразований. Рак ЩЖ был заподозрен только во время интраоперационной ревизии, в связи с чем пациентам была проведена тиреоидэктомия и удаление опухоли ОЩЖ. Гистологическое исследование выявило папиллярную микрокарциному ЩЖ (в первом случае одностороннюю, во втором – двустороннюю) и АА ОЩЖ. Большая осведомленность специалистов о сочетании ПРЩЖ с атипической аденомой ОЩЖ позволит расширить настороженность эндокринологов и хирургов, своевременно оценить возможную патологию ЩЖ у пациентов с ПГПТ, тем самым применить адекватный объем вмешательства в ходе одной операции.

Intrathyroidal Parathyroid Carcinoma: An Atypical Thyroid Lesion

Parathyroid carcinoma is a rare endocrine malignancy that is typically difficult to diagnose at presentation. Here, we report a 63 year-old man who had symptomatic hypercalcemia. Investigations revealed a thyroid nodule and a lateral neck mass that was biopsied and diagnosed as "suspicious for a neuroendocrine neoplasm." He underwent total thyroidectomy with central and left neck node dissection. Histology and immunohistochemistry revealed an intrathyroidal angioinvasive parathyroid carcinoma with lymph node metastases. The tumor showed loss of parafibromin expression; germline testing revealed no pathogenic germline variants of CDC73, suggesting either a cryptic germline variant or a sporadic malignancy. Multiple pulmonary nodules consistent with metastatic disease explained persistent hypercalcemia and the patient was treated with denosumab as well as Sorafenib resulting in early regression of the lung nodules. This case illustrates an unusual parathyroid carcinoma with respect to anatomic presentation and the importance of complete pathological workup in securing the diagnosis. The management of these rare malignancies is discussed.

The dangers of parathyroid biopsy

Background

We report an unusual case of a 66-year-old female with a suspicious thoracic outlet mass presenting with severe biochemical hyperparathyroidism and classic hypercalcemic symptoms of renal and bone involvement.

Case Presentation

There was clinical suspicion for parathyroid carcinoma, further supported by intra-operative findings. However, the final pathology described a primary hyperceullar parathyroid lesion with pathognomonic changes secondary to fine-needle aspiration (FNA) biopsy, along with a separate parathyroid lesion likely resulting from seeding along the needle tract. Upon further review, record of a remote FNA was discovered. This case highlights the complications associated with parathyroid FNA resulting in a diagnostic challenge and raising the possibility of malignancy.

Conclusions

We therefore recommend to take caution when there is a prior parathyroid FNA, as it can present with the risks of a secondary lesion from seeding and increase resemblance of malignancy both clinically and through pathologic diagnosis.

Intraoperative ex vivo parathyroid aspiration: A point-of-care test to confirm parathyroid tissue

BACKGROUND

Ex vivo aspiration of a parathyroid gland with intraoperative parathyroid hormone determination is a method for intraoperative confirmation of parathyroid tissue. The aim of this study was to describe the use and applicability of this technique at a single, high-volume institution.

METHODS

This is a retrospective review of patients who underwent parathyroidectomy and ex vivo aspiration of suspected, abnormal parathyroid tissue for intraoperative parathyroid hormone level (pg/mL). Sensitivity and specificity were calculated for aspirate intraoperative parathyroid hormone levels which were compared with the baseline serum aspirate intraoperative parathyroid hormone obtained prior to parathyroid excision in each patient.

RESULTS

Of 921 tissue aspirates, 847 (92%) were confirmed as parathyroid on histopathology, with a mean ± standard deviation aspirate intraoperative parathyroid hormone of 3,838 ± 1,615 pg/mL. The 847 aspirates included 833 (98%) with aspirate intraoperative parathyroid hormone levels greater than the serum aspirate intraoperative parathyroid hormone and 14 (2%) with aspirate intraoperative parathyroid hormone levels less than the serum aspirate intraoperative parathyroid hormone; 74 (8%) aspirates were not parathyroid tissue, with a mean aspirate intraoperative parathyroid hormone level of 25 ± 12.7 pg/mL. An aspirate intraoperative parathyroid hormone ≥1.5 times the serum aspirate intraoperative parathyroid hormone represented the optimal threshold for confirmation of parathyroid tissue.

CONCLUSION

Intraoperative ex vivo aspiration of presumed parathyroid gland is a sensitive and specific point-of-care method to confirm the presence of parathyroid tissue. An aspirate intraoperative parathyroid hormone ≥1.5 times greater than the baseline serum aspirate intraoperative parathyroid hormone minimizes the likelihood of misidentifying parathyroid tissue.

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.

Parathyroid: The Pathology of Hyperparathyroidism

This review focuses on the pathologic entities associated with hyperparathyroidism in humans. A discussion of the lesions, their embryology, and pathologic features is included. Immunohistology, cytopathology, and a brief overview of molecular aspects of the lesion are included.

Risks and benefits of parathyroid fine-needle aspiration with parathyroid hormone washout

OBJECTIVE

To describe the experience with parathyroid fine-needle aspiration (FNA) and parathyroid hormone (PTH) washout at Mayo Clinic Rochester, Rochester, Minnesota.

METHODS

We retrospectively reviewed all parathyroid FNA procedures performed at Mayo Clinic Rochester between January 2000 and December 2007. Clinical, biochemical, and imaging information, parathyroid FNA procedure, and cytology, surgical, and pathology reports were reviewed, and descriptive statistics, sensitivity, specificity, and positive predictive values are presented.

RESULTS

During the study period, 75 parathyroid FNAs were performed on 74 patients. Cytology results were available for 74 of 75 procedures, with only 31% interpreted as parathyroid cells. PTH washout was performed in 67 patients (91%). Parathyroid FNA with PTH washout had a sensitivity of 84%, specificity of 100%, positive predictive value of 100%, and accuracy of 84%. At the time of surgical treatment, 2 patients were noted to have an inflammatory response from the parathyroid FNA biopsy, 1 had a parathyroid abscess, and 2 had a hematoma. In 3 of these 5 patients, the necessary conversion of a minimally invasive surgical procedure to the standard surgical approach prolonged the surgical time.

CONCLUSION

Parathyroid FNA with PTH washout had a superior performance in comparison with parathyroid scanning or ultrasonography alone. The main limitations of parathyroid FNA with PTH washout are (1) the need for initial identification of a potential parathyroid adenoma by ultrasonography and (2) the number of false-negative results. Parathyroid FNA resulted in complications affecting the surgical procedure in 3 patients.

Thyroid diseases cause mismatch between MIBI scan and neck ultrasound in the diagnosis of hyperfunctioning parathyroids: usefulness of FNA-PTH assay

DESIGN

To evaluate the efficacy of the main tools in the diagnostic localization of hyperfunctioning parathyroids (HP) in primary hyperparathyroidism (pHPT) with concomitant thyroid diseases.

METHODS

Forty-three patients with pHPT associated with nodular goiter (NG, n=32) and/or autoimmune thyroid diseases (AITDs, n=11) for a total of 63 neck lesions were considered. Sixteen patients displaying HP (16 lesions), unequivocally localized by sestaMIBI scintigraphy (MIBI) and neck ultrasound (US) (group I), were compared with 27 patients (47 neck lesions) displaying equivocal parathyroid localization (group II). In all cases, neck US, MIBI scan, cytology, and parathyroid hormone assay in fine-needle aspiration washout fluid (FNA-PTH) were performed. All patients finally underwent surgery.

RESULTS

According to histological examination, high FNA-PTH values (>103 pg/ml) correctly identified all HP in both groups of patients (100% of sensitivity and specificity). Both MIBI and US correctly identified all HP only in group I patients; in contrast, four patterns of mismatch between these techniques were observed in group II patients, leading to low diagnostic performances of neck US (71.4% sensitivity and 78.9% specificity) and of MIBI scan (35.7% sensitivity and 42.1% specificity). The latter was due to both false-negative (mainly in AITD) and false-positive (mainly in NG) scan images.

CONCLUSIONS

Coexistent thyroid diseases are responsible for mismatch between MIBI and US images resulting in equivocal HP localization. In these cases, FNA-PTH resulted in the most accurate tool to identify HP. However, although safe, it should be advised only to patients with uncertain HP localization.

Diagnostic aspiration of parathyroid adenomas causes severe fibrosis complicating surgery and final histologic diagnosis

OBJECTIVE

To determine whether fine-needle aspiration (FNA) of parathyroid adenomas may cause a severe fibrotic reaction of the gland and surrounding structures, making surgery more difficult and histology more confusing.

DESIGN

A study was conducted over a 33-month period to compare the operative findings of 30 patients who underwent FNA of a parathyroid adenoma to those of 3000 patients who had not had their parathyroid tumor aspirated. Each patient's normal parathyroid glands also served as internal controls. All aspirations were performed by referring physicians under direct ultrasound guidance within 3 months of surgery, and all adenomas were located in routine positions. Patients who had previous thyroid or parathyroid surgery were not included. Patients with secondary or tertiary hyperparathyroidism were not included.

MAIN OUTCOME

The control group (non-FNA) showed a fibrotic reaction in 127 (4.3%) tumors appreciated by the surgeon and recognized on histology. In contrast, tumors undergoing FNA had a dense and often severely fibrotic reaction seen at surgery in 19 of 30 (63%) (p < 0.0001) and on histology in 23 of 30 (77%) (p < 0.0001). The fibrotic reaction appeared to mimic malignancy on histology and increased in occurrence with increased numbers of aspiration passes and larger needle bore (p < 0.05). No normal glands (n > 7500) or hyperplastic glands (n = 488) demonstrated fibrosis in any patient. Tumors that were aspirated required an eightfold increase in time to remove (p < 0.005) and more than doubled the total operative time (p < 0.05).

CONCLUSIONS

FNA of parathyroid adenomas can cause a severe fibrotic process that typically involves adjacent tissues. This reaction dramatically increases the difficulty of surgical resection, often requiring microdissection techniques to preserve nerves and assure complete removal. The fibrosis can cause confusing histology mimicking malignancy. FNA of parathyroid adenomas should be avoided unless absolutely necessary.