Preoperative prediction of parathyroid carcinoma in an Asian Indian cohort

A retrospective study on a nomogram combining clinical and ultrasound parameters for differentiating solitary parathyroid adenoma from carcinoma or atypical tumors

Objective

Parathyroid carcinoma (PC) and atypical parathyroid tumor (APT) are rare malignant parathyroid disorders with varying degrees of recurrence risk. The aim of this study was to determine an effective model for discriminating PC/APT among solitary parathyroid lesions.

Methods

A total of 439 patients with histologically confirmed primary hyperparathyroidism were retrospectively enrolled. The training cohort comprised 207 patients, the validation cohort comprised 52 patients from Hospital I, and the external validation cohort comprised 180 patients from Hospital II. All patients were diagnosed in the parathyroid adenoma (PA) group and the APT/PC group. The clinical and ultrasonic features of the two patient groups were compared. Multivariate logistic regression analysis was conducted to identify independent risk factors for APT/PC. A nomogram was built based on multivariate logistic regression analysis. Model discrimination was assessed using receiver operating characteristic (ROC) curve analysis. The area under the curve (AUC), sensitivity, specificity, and accuracy were reported. Decision and calibration curve analyses were performed to assess the clinical value and calibration of each model, respectively.

Results

In the training set, there were 181 cases of PA and 26 cases of APC/PC. Intact parathyroid hormone (iPTH) [odds ratio (OR): 1.019, 95% confidence interval (CI): 1.008-1.032], shape (OR: 16.625, 95% CI: 5.922-51.883), and relation with the thyroid capsule (OR: 3.422, 95% CI: 1.455-9.152) were independent predictive factors associated with the risk of APT/PC. The AUCs for training and internal and external validation were 0.929, 0.962, and 0.965, respectively. The accuracy, sensitivity, and specificity were 86%, 96%, and 85% in the training cohort; 92%, 100%, and 90% in the validation cohort; and 88%, 100%, and 88% in the external validation cohort, respectively. In addition, calibration plots graphically showed good agreement in the presence of the APT/PC group between risk estimation by the nomogram and histopathologic confirmation of surgical specimens. DCA in the current study showed that the nomogram was more effective than all-patient treatment or no treatment over a wide range of threshold probabilities.

Conclusions

Ultrasonic features in combination with iPTH levels may be an applicable model for predicting potentially malignant parathyroid tumors and has a better potential to facilitate preoperative decision-making.

Adolescent primary hyperparathyroidism

Adolescent primary hyperparathyroidism (PHPT) is a rare endocrine disorder bearing distinctions from the adult form. This review examines its unique aspects, focusing on clinical presentation, genetic etiologies, genotype-phenotype correlations, and therapeutic management. Adolescent PHPT often has a genetic basis, whether familial, syndromic, or apparently sporadic, and identifying the underlying genetic cause is important for patient care. The clinical presentation is predominantly symptomatic worldwide. Unique manifestations in this age group include rickets, short stature, and slipped capital femoral epiphysis. Genotype-specific differences are evident in the adolescent PHPT characteristics. Diagnostic evaluation requires careful interpretation of biochemical and dual-energy X-ray absorptiometry findings using age and gender-specific reference ranges, with targeted screening for syndrome-associated neoplasms. Surgery remains the cornerstone of management. Current knowledge gaps in their management include treatment protocols for multiple endocrine neoplasia type 1-associated PHPT, the efficacy and safety of nonsurgical options, and long-term post-surgical outcomes.

The polar vessel sign: insights from CT imaging analysis in Asian Indian primary hyperparathyroidism

PURPOSE

Data on the polar vessel sign (enlarged feeding vessel terminating in parathyroid lesions) on four-dimensional computed tomography (4D-CT) is limited. We performed a retrospective analysis to determine the prevalence, predictors, and adjunctive utility of polar vessel sign in pre-operative 4D-CT of patients with primary hyperparathyroidism (PHPT).

METHODS

One radiologist blinded to the patients' details reported the 4D-CT of eighty-four operated patients with histopathology-proven single-gland PHPT. Two protocols were used to obtain arterial-phase images: timed via bolus tracking (n = 41) or fixed at 20 s after contrast injection (n = 43).

RESULTS

Seventy-one patients were symptomatic for PHPT, with median serum calcium 12.1 mg/dL. On the arterial phase of 4D-CT, 88.1% of lesions had the polar vessel sign, including 7/9 asymptomatic patients, 6/6 parathyroid carcinomas, and 3/4 ectopic(1:mediastinum, 2:thyro-thymic ligament). Predictors of polar vessel sign were maximum lesion dimension (2.2 vs. 1.4 cm; P = 0.03), solid-cystic CT morphology (47.3% vs. none; P = 0.004), and bolus tracking-timed arterial phase (55.4% vs. none; P = 0.001). Of these, bolus tracking improved the polar vessel's visualization (100% vs. 76.7%; P = 0.001) independent of lesion dimension and solid-cystic morphology. The latter two predicted polar vessel sign in images obtained at a fixed interval (20 s). A significantly lower proportion of bolus tracking-timed scans had lesion percentage arterial enhancement (PAE) < 128.9% (2/41 vs. 9/43; P = 0.04). Even with suboptimal PAE, the polar vessel helped identify 9/11 lesions.

CONCLUSION

The polar vessel sign demonstrated an additive role to PAE during CT reporting. Bolus tracking is valuable in optimizing vessel and tumor arterial enhancement and is easily incorporated into parathyroid 4D-CT protocol.

Extremely High Preoperative Parathyroid Hormone Associated With Severe Postoperative Hungry Bone Syndrome-Induced Delirium in a Case of Parathyroid Carcinoma in Vietnam: A Case Report

Parathyroid carcinoma (PC) is one of the rarest cancers, accounting for less than 1% of all cases of primary hyperparathyroidism worldwide. The preoperative level of parathyroid hormone (PTH) has been taken as an essential index in diagnosing and prognosting PC. The conventional range of preoperative PTH was three to 10 times higher than the upper limit. Recently published studies have shown a significantly extensive range of preoperative levels of PTH in different countries, which might change our opinion on probable preoperative PTH levels in PC and its related postoperative complications. We present a case of a 47-year-old Vietnamese male patient suffering from PC with preoperative PTH up to 60 times higher than the upper limit. After the surgery, the patient developed hungry bone syndrome (HBS), manifesting through severe hypocalcemia at 0.04 mmol/l of ionized calcium, which altered his mental status for one week and required a hefty dose of calcium to normalize the patient's plasma calcium levels. There seems to be no upper limit for PTH levels in PC. A significantly high level of preoperative PTH is an essential warning sign of severe HSB developing postoperatively.

Predictive Ability of Rule of 3 in Parathyroid Cancer: Outcomes from a South Asian Cohort

BACKGROUND

Preoperative diagnosis of parathyroid cancer (PC) where possible allows for en-bloc resection of the tumour, which is associated with excellent prognosis. The rule of >3 (size of tumour larger than 3 cm; corrected calcium more than 3 mmol/L) as proposed by Schulte and Talat has a specificity of 95% in predicting malignancy in parathyroid neoplasms. We looked at the impact of rule of 3 in predicting malignancy and outcomes on intervention in a South Asian cohort.

METHODS

Patients who underwent parathyroid surgery between 2010 and 2023 at two tertiary referral centres were assessed. Patients with PC were selected and their clinicopathological parameters, treatment modalities, and outcomes were analysed.

RESULTS

Thirteen of 336 (3.8%) patients with a mean age of 61.8 (±17.5) years were diagnosed with PC during the study period. The highest mean preoperative values were PTH (92.4 ± 66.27 pmol/L), highest corrected calcium (3.21 ± 0.28 mmol/L), and alkaline phosphatase (419 IU/mL). Nine patients underwent en-bloc excision while the other had focussed parathyroidectomy. Recurrences were recorded in 2 (28.5%) patients over a mean follow-up period of 69 (±48.6) months. One patient with lung metastasis underwent video-assisted thoracic surgery. There was no disease specific mortality in this cohort during the study period.

CONCLUSIONS

In our experience, the predictive rule of 3 has low sensitivity to suspect PC preoperatively, resulting in limited usefulness in clinical practice. Outcomes appear to be less favourable with higher recurrence rates in cases where less than en-bloc resection is performed.

The clinicopathological features of lung metastases of parathyroid cancinoma

Parathyroid carcinoma(PC) is an extremely rare malignant tumor of the parathyroid glands. The lung is the most common target organ for PC distant metastases. In this study, twelve patients diagnosed with PC with lung metastases were enrolled in the study. Hematoxylin and Eosin(H&E) stained, immunohistochemical stained and next-generation sequencing (NGS) of a 425-gene panel were performed on tumor tissue samples. At the same time, we also evaluated its histopathologic characteristics. The results indicate that the microscopic examination of metastatic lesions reveals the same structure and characteristics as PC; the tumor was composed of relatively uniform cells organized in nests and separated by thin fibrous bands and abundant blood vessels. Immunohistochemical evaluation of Ki67, CyclinD1, PTH, SYN, CgA, and CD56 was useful in diagnosing PC with lung metastases. The most frequently genetic alterations were mutations of CDC73 and copy number variation (CNV) of MCL1, with a mutation rate of 25 %. In addition, the mutations of CDC73, ATM, TP53, ALK, ERBB2, MAP3K4, TSC1, CCND1 and CNV of CDK4, MCL1, SMARCB1 overlap between metastatic lesions and primary lesions. In conclusions, PC is a rare endocrine malignant tumor that is very difficult to diagnose preoperatively and prone to clinical recurrence or distant metastasis. Genetic mutations, presentation and histological characteristic were the basis for diagnosing PC with lung metastases.

Imaging Recommendations for Diagnosis and Management of Primary Parathyroid Pathologies: A Comprehensive Review

Parathyroid pathologies are suspected based on the biochemical alterations and clinical manifestations, and the predominant roles of imaging in primary hyperparathyroidism are localisation of tumour within parathyroid glands, surgical planning, and to look for any ectopic parathyroid tissue in the setting of recurrent disease. This article provides a comprehensive review of embryology and anatomical variations of parathyroid glands and their clinical relevance, surgical anatomy of parathyroid glands, differentiation between multiglandular parathyroid disease, solitary adenoma, atypical parathyroid tumour, and parathyroid carcinoma. The roles, advantages and limitations of ultrasound, four-dimensional computed tomography (4DCT), radiolabelled technetium-99 (99mTc) sestamibi or dual tracer 99mTc pertechnetate and 99mTc-sestamibi with or without single photon emission computed tomography (SPECT) or SPECT/CT, dynamic enhanced magnetic resonance imaging (4DMRI), and fluoro-choline positron emission tomography (18F-FCH PET) or [11C] Methionine (11C -MET) PET in the management of parathyroid lesions have been extensively discussed in this article. The role of fluorodeoxyglucose PET (FDG-PET) has also been elucidated in this article. Management guidelines for parathyroid carcinoma proposed by the American Society of Clinical Oncology (ASCO) have also been described. An algorithm for management of parathyroid lesions has been provided at the end to serve as a quick reference guide for radiologists, clinicians and surgeons.

Parathyroid carcinoma: Current management and outcomes – A systematic review

OBJECTIVE

Parathyroid carcinoma is rarely encountered in clinical practice. When faced with this clinical challenge, there is currently a paucity of evidence available for the optimal management of patients with parathyroid carcinoma. This systematic review synthesizes the available literature to evaluate the optimal management approach, thus providing guidance for future management.

METHODS

A systematic review was conducted according to PRISMA guidelines using Ovid MEDLINE, EMBASE, and PubMed databases for studies, published in English, reporting on parathyroid carcinoma. Full text of potentially eligible articles were reviewed by two authors independently and eligible studies selected. Treatment options and associated outcomes were evaluated. Descriptive statistics were used to describe pooled patient cohorts.

RESULTS

3203 articles were initially identified using the search criteria with 59 full-text articles then screened for eligibility. Seven articles, all retrospective studies, concerning 2307 patients (median 224/study). Parathyroidectomy alone was the most frequently utilised surgical approach across all studies, followed by en-bloc resection (with adjacent thyroid and/or nodal tissue). There was no difference in post-operative morbidity, mortality or survival between surgical approaches (p < 0.005). Patients who underwent either form of surgery had longer overall survival than those managed non-operatively (p < 0.005).

CONCLUSION

Surgical resection is the optimal treatment of parathyroid carcinoma. However there remains no consensus on the optimal extent of surgery, and as such future randomised prospective studies are necessary to evaluate the effects of different surgical approaches on morbidity, mortality and oncologic outcomes. Following resection, long-term surveillance with PTH is advised.

Parathyroid carcinoma: lessons from a rare malignancy of head and neck-a case series

Parathyroid carcinoma (PC) is a very rare head-neck malignancy. Because the symptoms of parathyroid carcinoma are similar to those of benign causes of hyperparathyroidism, it may be not easy to detect it before surgery. The management of PC after initial surgery will be perplexing because of the adequacy of surgery. We wish to describe the difficulties encountered throughout treatment using a literature review. We conducted a retrospective analysis of individuals with parathyroid carcinoma who had treatment at our department between 2017 and 2022. We gathered data on the clinical profile, investigations, management of hypercalcemia, surgical techniques, histopathological features, adjuvant therapy, and outcomes. We treated three patients with parathyroid carcinoma: Two patients with inferior parathyroid carcinoma and one with superior parathyroid carcinoma. Generalized weakness and bony pain are the predominant symptoms. In all cases, the tumor was located using 99Tc MIBI / SPECT scintigraphy and Ultrasonography. Hemithyroidectomy and tumor excision were done as the surgery of choice. All are disease-free at the 12th-month follow-up. We suggested that parathyroid hormone testing be performed in all bony fibrous lesions to rule out hyperparathyroidism. PC is a likely diagnosis when there is noticeable throat swelling, elevated PTH levels greater than 400 IU/L, and serum calcium levels greater than 15 mg/dL.

68 Ga-DOTATATE PET/CT imaging in endogenous hyperinsulinemic hypoglycemia: A tertiary endocrine centre experience

OBJECTIVE

Literature regarding utility of 68 Ga-DOTATATE PET/CT in insulinoma localization across various subgroups [benign/malignant/multiple endocrine neoplasia-1 (MEN-1) syndrome associated] remains scarce. In this study, the performance of 68 Ga-DOTATATE PET/CT was compared with contrast-enhanced computed tomography (CECT) and 68 Ga-NODAGA-Exendin-4 PET/CT (whenever available) in an endogenous hyperinsulinemic hypoglycemia (EHH) cohort.

DESIGN

Retrospective audit.

PATIENTS

EHH patients [N = 36, lesions (n) = 49, final diagnosis: benign sporadic insulinoma (BSI) (N = 20), malignant insulinoma (N = 4, n = 14), MEN-1 syndrome associated insulinoma (N = 9, n = 15), Munchausen syndrome (N = 2) and drug-induced hypoglycemia (N = 1)] having both preoperative imaging modalities (CECT and 68 Ga-DOTATATE PET/CT).

MEASUREMENTS

Per-lesion sensitivity (Sn) and positive predictive value (PPV) for histopathological diagnosis of insulinoma.

RESULTS

Sn and PPV of 68 Ga-DOTATATE PET/CT were 67.3% and 89.2%; 55% and 100%; 85.7% and 100%; and 66.7% and 77% for overall EHH, BSI, malignant, and MEN-1 syndrome associated insulinoma cohorts respectively. Despite having comparatively lower sensitivity in BSI cohort, 68 Ga-DOTATATE PET/CT localized a pancreatic tail lesion missed by other modalities. 68 Ga-DOTATATE PET/CT had comparatively higher sensitivity in malignant insulinoma than BSI cohort. 68 Ga-DOTATATE PET/CT also paved the way for successful response to 177 Lu-based peptide receptor radionuclide therapy (PRRT). In MEN-1 cases, lower PPV as compared with BSI was due to uptake in non-insulinoma pancreatic neuroendocrine tumours (Pan-NET).

CONCLUSIONS

68 Ga-DOTATATE PET/CT has supplemental role in selected cases of BSI with negative and/or discordant results with CECT and 68 Ga-NODAGA-Exendin-4 PET/CT. In malignant insulinoma, 68 Ga-DOTATATE-PET/CT has an additional theranostic potential. Interference due to uptake in non-insulinoma Pan-NET in MEN-1 syndrome may hinder insulinoma localization with 68 Ga-DOTATATE-PET/CT.

Giant parathyroid tumours in primary hyperparathyroidism: a systematic review

PURPOSE

Giant parathyroid adenoma (GPA) can present with severe biochemical derangement similar to the clinical presentation of parathyroid carcinoma (PC). This study aims to present the current evidence on surgical management of GPAs in primary hyperparathyroidism.

METHODS

A systematic review of the literature on GPAs was conducted following the PRISMA guidelines. Data on clinical, biochemical, preoperative diagnostic, and surgical methods were analysed.

RESULTS

Sixty-one eligible studies were included reporting on 65 GPAs in eutopic, ectopic mediastinal, and intrathyroidal locations (61.5%, 30.8%, and 7.7%, respectively). A palpable neck mass was present in 58% of GPAs. A total of 90% of patients had symptoms including fatigue, skeletal pain, pathological fracture, nausea, and abdominal pain. Ninety percent of patients had significant hypercalcaemia (mean 3.51 mmol/L; range: 2.59-5.74 mmol/L) and hyperparathyroidism with PTH levels on average 14 times above the upper limit of the normal reference. There was no correlation between the reported GPA size and PTH nor between GPA weight and PTH (p = 0.892 and p = 0.363, respectively). Twenty-four percent had a concurrent thyroidectomy for suspicious features, intrathyroidal location of GPA, or large goitre. Immunohistochemistry such as Ki-67, parafibromin, and galectin-3 was used in 18.5% of cases with equivocal histology. Ninety-five percent of GPAs were benign with 5% reported as atypical adenomas.

CONCLUSION

The reported data on GPAs are sparse and heterogeneous. In GPAs with suspicious features for malignancy, en bloc resection with concurrent thyroidectomy may be considered. In the presence of equivocal histological features, ancillary immunohistochemistry is advocated to differentiate GPAs from atypical adenomas and PCs.

Case Report and Systematic Review: Sarcomatoid Parathyroid Carcinoma-A Rare, Highly Malignant Subtype

BACKGROUND

Parathyroid carcinoma (PC) is a rare malignancy, the incidence of which is less than 1/1 million per year. Sarcomatoid parathyroid carcinoma (SaPC) is an extremely peculiar subtype; only three cases have been reported internationally. It consists of both malignant epithelial components and sarcomatoid components (mesenchymal origin) simultaneously. This "confusing" cancer exhibits higher invasiveness, and traditional surgery does not appear to achieve the expectation, which differs significantly from that of general PC.

OBJECTIVE

To characterize the clinicopathologic features of SaPC and explore similarities and differences between SaPC and general PC.

MATERIALS AND METHODS

We collected clinical data of SaPC cases from our center and literature. The SaPC case in our center was presented. To better understand the characteristics of SaPC, we also reviewed clinical information in general PC cases from our center and literature within the last 5 years, and a systematic review was performed for further comparison.

RESULTS

A 60-year-old woman was admitted for a neck mass and hoarseness. After the surgery, she was confirmed as SaPC and ultimately developed local recurrence at 3 months. Together with the reported cases from literature, four cases of SaPC (three cases from literature) and 203 cases of general PC (200 cases from literature) were reviewed. Both tumors showed obvious abnormalities in parathormone (PTH) level and gland size. Compared to general PC, SaPC has a later age of onset (60.50 ± 7.42 vs. 51.50 ± 8.29), relatively low levels of PTH (110.28 ± 59.32 vs. 1,156.07 ± 858.18), and a larger tumor size (6.00 ± 1.63 vs. 3.14 ± 0.70). For SaPC, all four cases were initially misdiagnosed as thyroid tumors (4/4). Spindle cell areas or transitional zones were common pathological features in SaPC cases (3/4).

CONCLUSION

SaPC is a very rare pathologic subtype of PC and appears to be much more easily misdiagnosed as a thyroid tumor. Spindle cell areas or transitional zones are highly possible to be pathological features in its sarcomatoid components. Despite many similarities, there are some differences between SaPC and general PC-SaPC does not show the obvious endocrine feature but stronger aggressiveness. Surgical treatment of SaPC does relieve life-threatening symptoms and improve quality of life even with recurrence in the short term.