Clinical and outcome comparison of genetically positive vs. negative patients in a large cohort of suspected familial hypocalciuric hypercalcemia

OBJECTIVE

Biochemical suspicion of familial hypocalciuric hypercalcemia (FHH) might provide with a negative (FHH-negative) or positive (FHH-positive) genetic result. Understanding the differences between both groups may refine the identification of those with a positive genetic evaluation, aid management decisions and prospective surveillance. We aimed to compare FHH-positive and FHH-negative patients, and to identify predictive variables for FHH-positive cases.

DESIGN

Retrospective, national multi-centre study of patients with suspected FHH and genetic testing of the CASR, AP2S1 and GNA11 genes.

METHODS

Clinical, biochemical, radiological and treatment data were collected. We established a prediction model for the identification of FHH-positive cases by logistic regression analysis and area under the ROC curve (AUROC) was estimated.

RESULTS

We included 66 index cases, of which 30 (45.5%) had a pathogenic variant. FHH-positive cases were younger (p = 0.029), reported more frequently a positive family history (p < 0.001), presented higher magnesium (p < 0.001) and lower parathormone levels (p < 0.001) and were less often treated for hypercalcemia (p = 0.017) in comparison to FHH-negative cases. Magnesium levels showed the highest AUROC (0.825, 95%CI: 0.709-0.941). The multivariate analysis revealed that family history and magnesium levels were independent predictors of a positive genetic result. The predictive model showed an AUROC of 0.909 (95%CI: 0.826-0.991).

CONCLUSIONS

The combination of magnesium and a positive family history offered a good diagnostic accuracy to predict a positive genetic result. Therefore, the inclusion of magnesium measurement in the routine evaluation of patients with suspected FHH might provide insight into the identification of a positive genetic result of any of the CaSR-related genes.

Genomic Profiling Reveals the Variant Landscape of Sporadic Parathyroid Adenomas in Chinese Population

OBJECTIVE

To define somatic variants of parathyroid adenoma (PA) and to provide novel insights into the underlying molecular mechanism of sporadic PA.

METHODS

Basic clinical characteristics and biochemical indices of 73 patients with PA were collected. Whole-exome sequencing was performed on matched tumor-constitutional DNA pairs to detect somatic alterations. Functional annotation was carried out by ingenuity pathway analysis afterward. The protein expression of the variant gene was confirmed by immunohistochemistry, and the relationship between genotype and phenotype was analyzed.

RESULTS

Somatic variants were identified in 1549 genes, with an average of 69 variants per tumor (range, 13-2109; total, 9083). Several novel recurrent somatic variants were detected, such as KMT2D (15/73), MUC4 (14/73), POTEH (13/73), CD22 (12/73), HSPA2 (12/73), HCFC1 (11/73), MAGEA1 (11/73), and SLC4A3 (11/73), besides the previously reported PA-related genes, including MEN1 (11/73), CASR (6/73), MTOR (4/73), ASXL3 (3/73), FAT1 (3/73), ZFX (5/73), EZH1 (2/73), POT1 (2/73), and EZH2 (1/73). Among them, KMT2D might be the candidate driver gene of PA. Crucially, 5 patients carried somatic mutations in CDC73, showed an aggressive phenotype similar to that of parathyroid carcinoma (PC), and had a decreased expression of parafibromin. Pathway analysis of recurrent potential PA-associated driver variant genes revealed functional enrichments in the signaling pathway of Notch.

CONCLUSION

Our study expanded the pathogenic variant spectrum of PA and indicated that KMT2D might be a novel candidate driver gene and be considered as a diagnostic biomarker for PA. Meanwhile, CDC73 mutations might be an early developmental event from PA to PC. The results provided insights into elucidating the pathogenesis of parathyroid tumorigenesis and a certain basis for clinical diagnosis and treatment.

Clinical characteristics of primary parathyroid adenoma and its relationship with coexisting papillary thyroid carcinoma: a clinical retrospective study

Background

Parathyroid adenoma (PA) is a common but relatively poorly understood endocrine tumor. A significant number of PA patients also have papillary thyroid carcinoma (PTC). The clinicopathological characteristics of PA and its relationship with PTC need further study.

Methods

The clinical data of 99 PA patients were reviewed and the clinicopathologic features of PA were analyzed. PTC occurred in 22 PA patients. The clinicopathologic features of 22 patients with PA + PTC and 77 patients with PA alone were compared. According to age, gender and thyroid surgery methods, 22 PA + PTC patients were matched with 1,123 patients with PTC alone during the same period. The pathological characteristics of the two groups of patients were compared. All data analysis was performed using SPSS23.0, variables were compared by t-test, chi square test or Mann Whitney U-test as appropriate.

Results

Ninety-nine PA patients (21 males, 78 females) with a median age of 51 [10-80] years were included. The preoperative parathyroid hormone (PTH) (P=0.007) and preoperative blood calcium (P=0.036) of male patients were higher than those of female patients, and the proportion of asymptomatic patients (P=0.008) and postoperative PTH level (P=0.013) were lower. The preoperative PTH level (P=0.002), preoperative blood calcium level (P=0.004), preoperative alkaline phosphatase (ALP) level (P=0.018) and postoperative PTH levels (P=0.023) in PA + PTC group were lower than those in PA group. The asymptomatic rate was higher in PTC + PA group than that in PA group (P<0.001). There was no statistical difference between PA + PTC group and PTC group in multifocal tumor, capsule invasion, lymph node metastasis (P>0.05). The lymph node metastasis rate in PA + PTC group (9/215) was significantly lower than that in PTC group (37/337) (P=0.005).

Conclusions

PA exhibited the following characteristics: occurred in all age groups; more common in women but more severe in men; more located in the lower pole. The coexistence of PTC and PA did not promote the progression of PA, nor did it increase the aggressiveness of PTC. Conversely, their co-existence may lead to early diagnosis of the disease. PA patients (22.2%) also have PTC, so surgeons should pay attention to thyroid disease to prevent the need for reoperation.

Is total endoscopic parathyroidectomy an acceptable treatment for patients with primary hyperparathyroidism due to a presumed solitary adenoma?-comparison of minimally invasive total endoscopic parathyroidectomy and open minimally invasive parathyroidectomy

Background

Remote-access thyroidectomy and its cosmetic merit have been widely accepted, but remote-access parathyroidectomy has not become common. There are few reports about the risks and effectiveness of a remote-access endoscopic parathyroidectomy. Herein, we evaluated the risks and benefits of total endoscopic parathyroidectomy (TEP) for patients with primary hyperparathyroidism (PHPT). We retrospectively compared the surgical outcomes of TEP and open minimally invasive parathyroidectomy (MIP).

Methods

We analyzed the cases of 28 patients with PHPT who were scheduled to undergo a MIP at Mita Hospital (Tokyo) during the period from April 2015 to March 2019, all of whom were presumed preoperatively to have a single adenoma.

Results

Eleven of the patients underwent a TEP (10 females, one male; mean age 54.2 years). The other 17 patients underwent an open MIP (11 females, 6 males; mean age 63.5 years). The younger patients and the females tended to select endoscopic surgery as their treatment. The operation time was significantly longer in the TEP group compared to the open MIP group (106 vs. 50 min; P<0.001). Common postoperative complications (such as recurrent laryngeal nerve paralysis and seroma) did not occur in this series. For the TEP patients who did not undergo a partial thyroidectomy, the mean amount of drainage on the first postoperative day was only 19±10 mL. The operative cure rate of the minimally invasive parathyroidectomies was 96.4%.

Conclusions

TEP is a good surgical procedure for hyperparathyroidism caused by a single adenoma, and it achieves superior cosmetic results without increasing the rate of complications.

Multiple bone brown tumor secondary to primary hyperparathyroidism: a case report and literature review

Bone brown tumors secondary to primary hyperparathyroidism (PHPT) are rare and only around 2-5% of PHPT patients have multiple bone brown tumor lesions, which are also uncommon in literatures. We found a female patient who got misdiagnosis of multiple malignant bone tumors in our clinical work, she was eventually diagnosed as a brown tumor secondary to hyperparathyroidism. This article records the diagnosis and treatment process, and summarizes similar case reports in the past decade to provide experience in diagnosis and treatment of similar cases that may occur in the future.