Intrathyroidal Parathyroid Carcinoma: An Atypical Thyroid Lesion

Parathyroid carcinoma: molecular therapeutic targets

Parathyroid carcinoma (PC) is an extremely rare malignant tumor of the parathyroid glands, accounting for less than 1% of primary hyperparathyroidism, commonly characterized by severe and unmanageable hypercalcemia, aggressive behavior, high metastatic potential, and poor prognosis. PC manifests prevalently as a sporadic tumor and only occasionally it is part of congenital syndromic and non-syndromic endocrine diseases. Molecular pathogenesis of this form of parathyroid tumor is not fully elucidated and it appears to be caused by multiple genetic and epigenetic drivers, differing among affected patients and not yet clearly stated in distinguishing PC from the benign parathyroid adenoma (PA). Congenital forms of PC have been prevalently associated with germline heterozygous loss-of-function mutations of the CDC73 tumor suppressor gene, both in the context of the hyperparathyroidism jaw-tumor syndrome (HPT-JT) and of the isolated familial hyperparathyroidism (FIPH). Currently, surgical en bloc resection of affected gland(s) and other involved structures is the elective therapy for both primary and recurrent PC. However, it usually results ineffective for advance and metastatic disease, and a high percentage of post-operative recurrence is reported. Targeted medical therapies for surgically untreatable PC, based on the molecular profile of PC samples, are, therefore, needed. The characterization of genetic and epigenetic alterations and deregulated pathways in PC samples will be of fundamental importance to tailor treatment for each patient. Here, we reviewed main findings on molecular pathogenetic aspects of PC, and the current state of the art of therapies.

Intrathyroidal parathyroid adenomas: Scoping review on clinical presentation, preoperative localization, and surgical treatment

Intrathyroidal parathyroid adenomas (IPAs) are a rare cause of primary hyperparathyroidism. They are often difficult to localize preoperatively and intraoperatively, making diagnosis and treatment challenging. Current data on IPAs are sparse and fragmented in the literature. This makes it difficult to compare the effectiveness of different imaging and surgical techniques. To address this issue, this scoping review maps the literature on IPAs, focusing on four domains: clinical presentation, current localization methods, different surgical techniques, and histopathological features. A search of MEDLINE, Embase, and the Cochrane Library was conducted, with 19 studies meeting the inclusion criteria. The characteristics of IPAs on ultrasound, fine-needle aspiration, CT, MRI, sestamibi-based techniques, and selective venous sampling are summarized. Emerging imaging modalities, including autofluorescence, are introduced. Surgical methods and intraoperative factors that correlate with high success rates for removal are highlighted. This review also identifies gaps in knowledge to guide further research into this area.

Successful Control of Hypercalcemia with Sorafenib, Evocalcet, and Denosumab Combination Therapy for Recurrent Parathyroid Carcinoma

Parathyroid carcinoma (PC) is a rare type of endocrine cancer. Recurrence and metastasis are common after surgery, and refractory hypercalcemia often leads to a poor prognosis. However, there are currently no specific strategies for PC recurrence. We herein report a 61-year-old Japanese man with metastatic PC who was treated with sorafenib, a multikinase inhibitor. In this case, the serum calcium level was under control for 10 months after the initiation of sorafenib. This case suggests that combination therapy with sorafenib, evocalcet, and denosumab may be an alternative, stronger management option for refractory hypercalcemia in recurrent PC.

Intrathyroidal parathyroid carcinoma presenting as thyroid nodule: Case report of unusual location

Introduction

Parathyroid carcinoma (PC) is considered a rare and uncommon malignancy. Its prevalence is about 0.005% of all cancers. Intrathyroidal location is rare, rendering preoperative diagnosis tedious. Until now, around 700 cases of PC have been documented, reportedly, among them, less than 21 cases of intrathyroidal parathyroid carcinoma have been described in the literature. We report a case of intrathyroidal PC that was taken for a suspicious thyroid nodule, with a literature review.

PRESENTATION OF THE CASE: Our case is an asymptomatic intrathyroidal PC imitating a suspicious thyroid nodule, in a 54-year-old woman. A literature review was performed about clinical, radiological features, histopathological findings, and therapeutic options.

Discussion

The diagnosis of asymptomatic intrathyroidal parathyroid carcinoma, similar to our case report, is even more difficult, our patient had no symptoms of hypercalcemia. Surgery is the cornerstone of the treatment. A better chance to cure this disease is conditioned by complete surgical resection with negative margins microscopically, that was the case of our patient with a very good clinical course after 12 months of follow-up.

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Parathyroid Carcinoma Is an Uncommon Endocrine Malignancy, Making Approximately 0.005% of All Cancers and 0,5%–2% of Patient With Primary Hyperparathyroidism.

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Intrathyroidal Location Is Rare and Make Preoperative Suspicion and Diagnosis Challenging.

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Approximately 700 Cases of Parathyroid Carcinoma Have Been Reported to Date and, to The Best of Our Knowledge, Less Than 24 Cases of Intrathyroidal Parathyroid Carcinoma Has Been Previously Documented.

Intrathyroidal Parathyroid Carcinoma: Case Report and Literature Review

Intrathyroidal parathyroid carcinoma (PC) is a rare malignancy that is usually difficult to diagnose. We present a case of a 31-year-old male with a history of hyperparathyroidism who was found to have intrathyroidal PC upon review of immunostains along with a review of the current literature. A systematic review of the literature utilizing the PubMed database identified 24 relevant, full-text articles. 25 cases were analyzed, including our own report. The case of a 31-year-old man with a history of hyperparathyroidism managed with subtotal thyroidectomy and subtotal parathyroidectomy who had persistent hypercalcemia and elevated parathyroid hormone. Abnormal radiotracer uptake was noted in the left thyroid gland. Neck exploration with left parathyroidectomy and revision thyroidectomy was performed. A candidate left inferior parathyroid was found within the left thyroid lobe remnant and identified as parathyroid carcinoma. Immunostains determined an intrathyroidal parathyroid carcinoma. The literature review shows the average presenting age was 50.9 years. 54.17% (CI, 43-82%) of affected patients are female. Right-sided thyroid involvement is seen in 54.17% (CI, 34-74%) of cases. The inferior aspect of the thyroid is involved in 66.67% of cases (CI, 53-89%). Intrathyroidal parathyroid carcinoma is a rare and challenging diagnosis due to similarities with other more common endocrine abnormalities. This review found that the inferior parathyroid is more likely to be located within the thyroid gland. Surgeons may consider aberrant anatomical locations, including intrathyroidal locations, for the inferior parathyroid glands.

A Nomogram Predicting the Overall Survival and Cancer-Specific Survival in Patients with Parathyroid Cancer: A Retrospective Study

PURPOSE

This study aimed to explore a visual model for predicting the prognosis of patients with parathyroid carcinoma (PC) and analyze related biochemistries in different groups of stage.

METHODS

The training dataset of 342 patients with PC was obtained from the Surveillance, Epidemiology, and End Results (SEER) database, and the validation dataset included 59 patients from The First Affiliated Hospital of Zhengzhou University. Univariate and multivariate Cox regression analyses were performed to evaluate significant independent prognostic factors. Based on those factors, nomograms and Web-based probability calculators were constructed to evaluate the overall survival (OS) and the cancer-specific survival (CSS) at 3, 5, and 8 years. The concordance index (C-index), receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were used to evaluate the nomogram in the training set and validation set. Moreover, biochemistries from the validation set were retrospectively analyzed in different groups of stage by Kruskal-Wallis test.

RESULTS

Age, marital status, tumor size, stage, lymph node status, and radiation were identified as prognostic factors of OS. In contrast, only tumor size and stage were predictive for CSS. The nomogram was developed based on these independent factors. The C-index, ROC curve, calibration curve, and DCA of the nomogram in both training and validation sets showed that the nomogram had good predictive value, stability, and clinical benefit in predicting 3-, 5-, and 8-year OS and CSS in PC patients. Among the 59 PC patients from our hospital, lower albumin (ALB) levels and higher postoperative parathyroid hormone (PTH) levels were found in patients with distant metastasis (Distant vs. Regional ALB levels: p = 0.037; Distant vs. Local ALB levels: p = 0.046; Distant vs. Regional postoperative PTH levels: p = 0.002; Distant vs. Local postoperative PTH: p = 0.002).

CONCLUSION

The established nomogram application can provide accurate prognostics for patients with PC in the Chinese population, but it must be validated on prospectively collected real-world data.

Fine-needle aspiration cytology of an intrathyroidal nodule diagnosed as squamous cell carcinoma: A case report

BACKGROUND

Both squamous cell carcinoma (SCC) and papillary thyroid carcinoma (PTC) are common malignant tumors in the neck. However, seldom has SCC of the thyroid been diagnosed. Further, cytological features of SCC and PTC have rarely been reported. The significance of fine-needle aspiration cytology (FNAC) in the diagnosis of neck masses has been established. Herein, we present an exceedingly rare case of an intrathyroidal SCC diagnosed using FNAC, along with its cytological features.

CASE SUMMARY

A 66-year-old man presented with a left-sided neck mass. Ultrasound examination showed an ill-defined nodule. The appearance was hypoechoic with a few hyperechoic spots. FNAC of the left thyroid nodule was performed. A cellular smear was obtained, and it showed a large number of neoplastic cells with rich cytoplasm and poor cell adhesion. Tumor cell nuclei showed coarse nuclear chromatin and a few enlarged prominent nucleoli. An increased nuclear/cytoplasm ratio was observed. Thus, malignancy was diagnosed without a confirmed tumor type. Percutaneous tumor biopsy was performed to make a definite diagnosis. The tumor cells showed typical squamous cell characteristics.

CONCLUSION

Head and neck SCC and PTC have different cytologies. Measures are needed to ensure accurate diagnosis using FNAC.

[The clinical practice guidelines for primary hyperparathyroidism, short version]

Primary hyperparathyroidism (PHPT) is an endocrine disorder of parathyroid glands characterized by excessive secretion of parathyroid hormone (PTH) with an upper normal or elevated blood calcium level. Classical PHPT refers to a symptomatic, multi-system disorder, wich can lead to a significant decrease in the quality of life, disability of patients, and even an increased risk of premature death. Hypercalcemia and the catabolic effect of PTH on various cells are considered as the main pathogenetic mechanisms of the PHPT associated complications. In the last two decades, there has been an increase in the incidence of PHPT, mainly due to the mild forms of the disease, primarily due to the routine calcium screening in North America, Western Europe and, Asia. High prevalence of the disease, as well as the variety of clinical manifestations, cause the attention of different specialists - physicians, rheumatologists, urologists, nephrologists, cardiologists and other doctors. This review cover the main issues of Russian guidelines for the management of PHPT, approved in 2020, including laboratory and instrumental methods, differential diagnosis, surgical and conservative approach, short-term and long-term follow-up. This guidelines also include the recommendations for special groups of patients with hereditary forms of PHPT, parathyroid carcinoma, PHPT during pregnancy.

Intrathyroidal parathyroid carcinoma: a case report and literature review

Parathyroid carcinoma is an uncommon endocrine malignancy comprising 0.5%–2% of patients with primary hyperparathyroidism. The probability of an intrathyroidal location is low (0.2%) and make preoperative suspicion and diagnosis challenging. Less than 20 cases of intrathyroidal parathyroid carcinoma have been reported. We introduce a case of intrathyroidal parathyroid carcinoma mimicking a suspicious thyroid nodule, and review the literature, with a focus on the role of adjuvant radiotherapy.

Synchronous intrathyroidal parathyroid carcinoma and thyroid carcinoma: case report and review of the literature

BACKGROUND

Parathyroid carcinoma is a rare endocrine malignancy, rarer when synchronous with a non medullary well differentiated thyroid carcinoma. Parathyroid carcinoma accounts of 0.005% of all malignant tumors and it is responsible for less than 1% of primary hyperparathyroidism. The intrathyroidal localization of a parathyroid gland is not frequent with a reported prevalence of 0.2%. Carcinoma of parathyroids with intrathyroidal localization represents an even rarer finding, reported in only 16 cases described in literature. The rare constellation of synchronous parathyroid and thyroid carcinomas has prompted us to report our experience and perform literature review.

CASE PRESENTATION

We herein report a case of a 63-years-old man with multinodular goiter and biochemical diagnosis of hyperparathyroidism. Total thyroidectomy with radio-guide technique using gamma probe after intraoperative sesta-MIBI administration and intraoperative PTH level was performed. The high radiation levels in the posterior thyroid lobe discovered an intrathyroidal parathyroid. Microscopic examination revealed a parathyroid main cell carcinoma at the posterior thyroidal left basal lobe, a classic papillary carcinoma at the same lobe and follicular variant of papillary carcinoma at the thyroidal right lobe. To the best of our knowledge, this is the first case documenting a synchronous multicentric non medullary thyroid carcinomas and intrathyroidal parathyroid carcinoma.

CONCLUSIONS

Our experience was reported and literature review underlining challenging difficulties in diagnostic workup and surgical management was carried out.

Fine needle aspiration of an intrathyroidal parathyroid carcinoma mimicking a primary thyroid anaplastic carcinoma: A case report with review of the literature

Intrathyroidal parathyroid carcinoma is an uncommon malignancy. A 46-year-old male presented with a left neck mass. Computed tomography (CT) scan revealed a hypodense mass in the left thyroid lobe along with evidence of metastatic lymphadenopathy. Aspiration of the left thyroid nodule was performed, and a diagnosis of malignancy was rendered, favoring a primary anaplastic carcinoma. Based on the cytologic diagnosis, the patient underwent a total thyroidectomy. Before the surgery, intact parathyroid hormone (PTH) and calcium level (PTH = 78 pg/mL; Calcium = 10.6 mg/dL) were found to be minimally elevated. On gross examination, a 3.2 cm mass within the left inferior thyroid lobe was seen. Histopathologic examination and ancillary studies supported the diagnosis of a parathyroid carcinoma. We, hereby present, an exceedingly rare presentation of an intrathyroidal parathyroid carcinoma with only minimal elevation of PTH and calcium, mimicking a primary anaplastic thyroid carcinoma on cytologic examination.

Parathyroid Cancer: A Review

Parathyroid cancer is one of the rarest causes of primary hyperparathyroidism and tends to present with more severe symptoms than its more benign counterparts. This article details various aspects of the disease process, including epidemiology, clinical presentation, and a step-wise diagnostic process for parathyroid cancer. This includes laboratory assessments as well as a proposed staging system. The en bloc principle of surgical intervention is detailed, as well as the current role of adjuvant treatments. A general guide to surveillance and the natural history of the disease is also outlined.

Parathyroid Cancer: A Review

Parathyroid cancer is one of the rarest causes of primary hyperparathyroidism and tends to present with more severe symptoms than its more benign counterparts. This article details various aspects of the disease process, including epidemiology, clinical presentation, and a step-wise diagnostic process for parathyroid cancer. This includes laboratory assessments as well as a proposed staging system. The en bloc principle of surgical intervention is detailed, as well as the current role of adjuvant treatments. A general guide to surveillance and the natural history of the disease is also outlined.

The Clinicopathological Spectrum of Parathyroid Carcinoma

Background: Parathyroid carcinoma is rare, representing <1% of primary hyperparathyroidism cases. Methods: Retrospective data of patients referred for evaluation of parathyroid disease between 2001 and 2018 were reviewed. The goal was to describe the clinical presentation, histopathologic characteristics, and treatment outcomes of parathyroid carcinoma. Results: We identified 8 cases of parathyroid carcinoma from the outpatient practice of a quaternary care Endocrine Oncology practice in Toronto, Canada. The clinical presentation was as follows: 5/8 cases (62.5%) of symptomatic hypercalcemia and 3/8 cases (37.5%) of a suspicious thyroid nodule. Hypercalcemia was evident in all 7 cases with pre-operative calcium measurements. Histopathologic features included: vascular invasion in 7/8 cases (87.5%) and immunohistochemical loss of either parafibromin, retinoblastoma, or p27 in all 8 cases. Additional treatment included: external beam radiotherapy in 5/8 cases (62.5%), chemotherapy for 2/8 patients (25%), and additional surgery for 3/8 patients (37.5%). Only 2 patients (25%) had long-term remission following surgical treatment, and the others had either persistent (3 patients) or recurrent disease (3 patients). Five patients developed metastatic disease, all involving lung. In one of two patients treated with Sorafenib there was evidence of regression of lung metastases. One patient died of disease progression. Conclusion: In this series of patients with parathyroid carcinoma largely presenting with symptomatic hypercalcemia and angioinvasive disease, only a minority achieved a durable remission. Lung was the most common site of distant metastasis. Surgery led to remission in two cases, but none of the six patients with persistent or recurrent disease ultimately achieved disease remission.