Germline Variants in Sporadic Pituitary Adenomas.

Context: Data on germline genetics of pituitary adenomas (PAs) using whole-exome sequencing (WES) are limited. Objective: This study investigated the germline genetic variants in patients with PAs using WES. Methods: We studied 134 consecutive functioning (80.6%) and nonfunctioning (19.4%) PAs in 61 female (45.5%) and 73 male patients (54.5%). Their median age was 34 years (range, 11-85 years) and 31 patients had microadenomas (23.0%) and 103 macroadenomas (77%). None of these patients had family history of PA or a known PA-associated syndrome. Peripheral blood DNA was isolated and whole-exome sequenced. We used American College of Medical Genetics and Genomics (ACMG) criteria and a number of in silico analysis tools to characterize genetic variant pathogenicity levels and focused on previously reported PA-associated genes. Results: We identified 35 variants of unknown significance (VUS) in 17 PA-associated genes occurring in 40 patients (29.8%). Although designated VUS by the strict ACGM criteria, they are predicted to be pathogenic by in silico analyses and their extremely low frequencies in 1000 genome, gnomAD, and the Saudi Genome Project databases. Further analysis of these variants by the Alpha Missense analysis tool yielded 8 likely pathogenic variants in 9 patients in the following genes: AIP:c.767C>T (p.S256F), CDH23:c.906G>C (p.E302D), CDH23:c.1096G>A (p.A366T), DICER1:c.620C>T (p.A207V), MLH1:c.955G>A (p.E319K), MSH2:c.148G>A (p.A50T), SDHA:c.869T>C (p.L290P) and USP48 (2 patients): c.2233G>A (p.V745M). Conclusion: This study suggests that about 6.7% of patients with apparently sporadic PAs carry likely pathogenic variants in PA-associated genes. These findings need further studies to confirm them.

An aggressive cabergoline-resistant, temozolomide-responsive macroprolactinoma due to a germline SDHB pathogenic variant in the absence of paraganglioma or pheochromocytoma.

Context: Germline succinate dehydrogenase subunit B (SDHB) pathogenic variants are characteristic of familial paraganglioma (PGL) syndrome type 4. This syndrome frequently presents with abdominal PGL and has high tendency for locally aggressive behavior and distant metastasis. The vast majority of pituitary adenomas (PAs) are sporadic. However, PAs can be part of a number of familial tumor syndromes such as multiple endocrine neoplasia type 1 (MEN 1) or more rarely in association with pheochromocytoma and PGL (referred to as 3P syndrome). Only a limited number of PAs in association with SDHB-related PGL has been reported and the vast majority occurred subsequently or simultaneously with pheochromocytoma/PGL (collectively abbreviated as PPGL). In this report, we describe a young patient who had a giant pituitary macroprolactinoma resistant to large doses of cabergoline (CBG) and external beam radiotherapy (XRT). The patient did not have personal history of PPGL but was found to carry a germline SDHB pathogenic variant. Case report: A 38-year-old woman presented with headache, visual disturbances and galactorrhea and was found to have a 34-mm macroprolactinoma. She was treated with CBG 3-4 mg per week but PA continued to grow and caused significant cranial pressure symptoms. She underwent two transsphenoidal surgeries with rapid tumor recurrence after each one. She received XRT but PA continued to grow. She was finally treated with temozolomide with excellent response. Whole exome and subsequent Sanger sequencing confirmed that she has a pathogenic monoallelic SDHB mutation (NM_003000:c.C343T, p.R115*). PA tissue showed loss of heterozygosity for the same mutation and absent SDHB immunostaining confirming the pathogenic role of this SDHB mutation. Conclusion: Germline SDHB mutations can rarely cause PA in the absence of PPGL. They should be considered as a possible cause of aggressiveness and resistance to dopamine agonists in similar cases.

Natural Course of the American Thyroid Association Response to Therapy Statuses (Dynamic Risk Stratification) in Differentiated Thyroid Cancer.

The concept of response to therapy in differentiated thyroid cancer (DTC) was introduced as a dynamic risk stratification used to assess the status of the disease at the time of the evaluation during the follow-up and the risk of recurrence in the future. Our aim in this study was to evaluate the natural course over time of different response to therapy statuses. METHODS: We studied 501 nonselected DTC patients (102 males and 399 females) with a median age of 37 years (interquartile range [IQR] 29-48). All patients underwent near-total or total thyroidectomy followed by I-131 ablation (initial management). RESULTS: Of the 501 patients, 387 patients (77.2%) did not have any additional therapuetic interventions after the initial management. In this group, the response to therapy status at the time of the first evaluation after I-131 (median 17 months, IQR 14-22) was an excellent response in 258 (66.7%), an indeterminate response in 101 (26.1%), biochemically incomplete in 17 (4.4%), and structurally incomplete in 11 patients (2.8%). The status changed spontaneously without any intervention in many of them. At the last follow-up visit (median duration 101 months, IQR 71-126), 357 patients (92.2%) achieved an excellent response, 4 (1%) an indeterminate response, 8 (2.1%) a biochemically incomplete status, 16 (4.1%) a structurally incomplete status, and 2 (0.5%) died secondary to DTC with a structurally incomplete status. The response to therapy in the other 114 patients who underwent additional interventions changed from before intervention to the last evaluation as follows: excellent response, 0 to 60 patients (52.6%), indeterminate response, 20 (17.5%) to 1 patient (0.9%), biochemically incomplete 25 (21.9%) to 10 patients (9%), and structurally incomplete 69 (60.5%) to 43 patients (37.7%). Overall, at the last evaluation, 417 (83.2%) were in an excellent response, 5 (1%) in an indeterminate response, 18 (3.6%) in a biochemically incomplete status, 50 (10.2%) in a structurally incomplete status, and 11 (2.2%) died secondary to DTC with a structurally incomplete status. CONCLUSIONS: The response to therapy at the initial evaluation is predictive of the long-term outcome. Most patients with the indeterminate response and some in the biochemically incomplete statuses spontaneously regress to an excellent status. Mortality and progression of DTC occur mostly in the structurally incomplete status.

How Does The AJCC/TNM Staging System Eighth Edition Perform in Thyroid Cancer at A Major Middle Eastern Medical Center?

OBJECTIVE: The American Joint Committee on Cancer tumor node metastasis (TNM) staging system eighth edition (TNM-8) for differentiated thyroid cancer (DTC) has been introduced as a replacement for tumor node metastasis staging system seventh edition (TNM-7). We present the first study from a Middle Eastern population comparing these 2 versions of the TNM staging system. METHODS: We compared TNM-8 with TNM-7 in 701 patients with DTC seen during a 3-year period with a median age of 37 years (6-83) and a female-to-male ratio of 558 (79.6%) to 143 (20.4%). RESULTS: The number (%) of patients within each stage in TNM-7 and TNM-8, respectively, are as follows: stage I = 503 (71.6%) and 583 (83.2%), stage II = 52 (7.4%) and 81 (11.4%), stage III = 53 (7.6%) and 6 (0.9%), and stage IV = 93 (13.2%) and 31 (4.6%). Overall, 172 patients (24.5%) were downstaged in TNM-8 compared to that in TNM-7, as follows: 26, 30, and 24 patients from stages II, III, and IV in TNM-7 to stage I in TNM-8; 23 and 32 patients from TNM-7 stages III and IV to TNM-8 stage II; 6 patients from stage IVa in TNM-7 to stage III in TNM-8; and 31 patients from stage IVc in TNM-7 to stage IVb in TNM-8. TNM-7 and TNM-8 predicted the long-term outcome well (median follow-up, 7.9 years), but Kaplan-Meier analysis showed better separation of cancer-specific survival in TNM-8 compared to TNM-7. CONCLUSIONS: Compared with TNM-7, TNM-8 approximately downstaged a quarter of DTC patients and was more robust in separating the outcome of different stages over time.

A novel claudin-10 mutation with a unique mechanism in two unrelated families with HELIX syndrome.

HELIX syndrome, characterized by hypohidrosis, electrolyte imbalance, lacrimal gland dysfunction, ichthyosis, and xerostomia due to claudin-10 (CLDN10) mutations, was recognized in 2017. Here we describe two unrelated Saudi families with this syndrome due to a novel CLDN10 mutation with a unique mechanism of CLDN10 inactivation. The two consanguineous families include 12 affected individuals (three siblings in family 1 and nine members in family 2). They presented with hypokalemia and the above-mentioned features of HELIX syndrome. The underlying mutation was detected by whole exome sequencing, confirmed by Sanger sequencing and functionally indicated by RT-PCR, electrophysiological studies and immunohistochemical staining of transfected HEK293 and MDCK C7 cells, and skin and kidney biopsy tissues. A novel biallelic single nucleotide deletion was identified in exon 5 of CLDN10 (NM_182848.3: c.647delC, p.P216Lfs∗19 for CLDN10a or NM_006984.4: c.653delC, p.P218Lfs∗21 for CLDN10b). The mutation led to frameshift and extension of the original termination codon by nine amino acids with loss of the C-terminus pdz-binding motif. Functional studies showed mRNA degradation and protein retention in intracellular compartments and that the pdz-binding motif is crucial for proper localization of claudin-10 in tight junctions. In the kidney, claudin-10 was replaced by translocation of claudin-2 (proximal tubule) and claudin-19 (thick ascending limb), and in the sweat gland by claudin-3 and occludin. However, these claudins did not functionally compensate for loss of claudin-10. Thus, this novel CLDN10 mutation identified in these two families disrupted the C-terminus pdz-binding motif of claudin-10 causing HELIX syndrome.

Course and Predictive Factors of Incomplete Response to Therapy in Low- and Intermediate-Risk Thyroid Cancer.

CONTEXT: Controversy surrounds the extent and intensity of the management of American Thyroid Association (ATA) intermediate- and low-risk patients with differentiated thyroid cancer (DTC). Understanding the natural history and factors that predict outcome is important for properly tailoring the management of these patients. OBJECTIVE: This work aims to study the natural course and predictive factors of incomplete response to therapy in low- and intermediate-risk DTC. PATIENTS AND METHODS: We studied a cohort of 506 consecutive patients [418 women (82.6%) and 88 men (17.4%)] with low and intermediate risk with a median age of 35 years (interquartile range [IQR], 27-46 years). We analyzed the natural course and the predictive factors of biochemically or structurally incomplete response. RESULTS: Of 506 patients studied, 297 (58.7%) patients were in the low-risk group and 209 (41.3%) were in the intermediate-risk group. Over a median follow-up of 102 months (IQR, 66-130 months), 458 (90.5%) patients achieved an excellent response, 17 (3.4%) had a biochemically incomplete status, and 31 (6.1%) had a structurally incomplete status. In univariable and multivariable analyses, age (≥ 33 years) (P < .0001, odds ratio 1.06 [1.04-1.08]) and lateral lymph node metastasis (LNM; P < .0001, odds ratio 3.2 [1.7-5.9]) were strong predictive factors for biochemically and structurally incomplete response to therapy. Sex, tumor size, multifocality, extrathyroidal extension, and lymphovascular invasion did not predict incomplete response to therapy. CONCLUSIONS: Patients with low- and intermediate-risk DTC have favorable outcomes. Age and lateral LNM are strong predictors of an incomplete response to therapy. This suggests that older patients and those with LNM should be managed and followed up more actively than younger patients and those without LNM.

One genotype, many phenotypes: SDHB p.R90X mutation-associated paragangliomas.

CONTEXT: SDHB p.R90X germline mutation is the most common genetic alteration in our patients with familial or apparently sporadic pheochromocytoma/paraganglioma (PPGL). OBJECTIVE: To analyze the clinical and pathological characteristics, response to therapy, and outcome of patients with SDHB p.R90X-associated PPGL and describe the clinical phenotypic variability in the patients carrying this mutation. METHODS: We reviewed the clinical and pathological characteristics and analyzed the phenotypic variability of all 13 patients that have SDHB p.R90X mutation-associated PPGL. RESULTS: Thirteen patients (five females and eight males). The median age at diagnosis was 23 years (range 8-43). Although the mutation was the same, there was significant phenotypic variability between patients and even within the same family. Four patients (30.8%) had a family history of PPGL and six patients (46%) had distant metastasis. Surgery of the primary tumor was performed in 11 patients (84.6%). Two patients had inoperable PPGL. Patients with metastasis received different combinations of chemotherapy, Lu177 radiotherapy, multikinase inhibitors, and external irradiation. Only five patients (38.5%) were in remission at a follow-up duration of 4-9 years. The other patients either died due to their disease progression (four patients, 30.8%) or continue to have progressive disease (two patients, 15.4%) or recurrence (one patient, 7.7%). Patients with distant metastasis were older, had larger primary tumors, were more likely to have a family history of PPGL and had a worse outcome. CONCLUSION: SDHB p.R90X mutation-associated PPGL have significant phenotypic variability and are associated with a high risk of distant metastasis and mortality.

Mutational profile and genotype/phenotype correlation of non-familial pheochromocytoma and paraganglioma.

About 30%-40% of patients with pheochromocytoma (PCC) and paraganglioma (PGL) have underlying germline mutations in certain susceptibility genes despite absent family history of these tumors. Here, we present mutational profile of 101 such patients with PCC/PGL (PPGL) from the highly consanguineous population of Saudi Arabia. Results: Of 101 cases with PPGL, 37/101 (36.6%) had germline mutations. Mutations were detected in 30 cases by PCR and direct Sanger sequencing and in 7 additional cases by NGS. The most commonly mutated gene was SDHB (21/101 cases, 20.8%) and the most common SDHB mutation was c.268C>T, p.R90X occurring in 12/21 (57%) cases. Mutations also occurred in SDHC (4/101, 3.96%), SDHD (3/101, 3%), VHL (2/101, 2%) and MAX (2/101, 2%) genes. The following genes were mutated in 1 patient each (1%), RET, SDHA, SDHAF2, TMEM127 and NF1. Metastatic PPGL occurred in 6/21 cases (28.6%) with SDHB mutations and in 1 case with SDHAF2 mutation. Patients and Methods: DNA was isolated from peripheral blood (53 patients) or from non-tumorous formalin fixed paraffin embedded (FFPE) tissue (48 patients). PCR and direct Sanger sequencing of RET, SDHx, VHL, MAX and TMEM127 genes were performed. Cases without mutations were subjected to whole exome sequencing using next generation sequencing (NGS). Conclusion: About 37% of PPGL without family history of such tumors harbor germline mutations. The most commonly mutated gene is SDHB followed by SDHC, SDHD, VHL, MAX and rarely RET, SDHA, SDHAF2, TMEM127 and NF1. SDHB mutations were associated with metastatic PPGL in more than a quarter of cases.

Correction to: Absence of EIF1AX, PPM1D, and CHEK2 mutations reported in Thyroid Cancer Genome Atlas (TCGA) in a large series of thyroid cancer.

The original version of this article unfortunately contained a mistake in the abstract and body of the article, the acronym TCGA should refer to "The Cancer Genome Atlas" not "Thyroid Cancer Genome Atlas". This has been corrected with this erratum.

Increased androgen secretion in patients with prolactinomas: the impact of altered HPA function.

BACKGROUND AND OBJECTIVES: Earlier studies suggested that hyperprolactinemia was associated with elevated serum DHEA-S levels. The importance of DHEA-S measurements in the diagnosis of adrenal insufficiency prompted us to assess adrenal androgen levels in hyperprolactinemic subjects with normal or impaired function. METHODS: Prospective study including 122 medically treated and 26 surgically patients with prolactinomas. Serum PRL, DHEA and DHEA-S levels were measured before and repeatedly after cabergoline therapy and also in the perioperative period of surgically treated patients. RESULTS: Serum PRL levels decreased (P < 0.001) in all 101 medically treated patients with normal HPA function from 728.3 ± 1507 reaching 29.1 ± 39 and 14.9 ± 24.4 µg/L at 3 and 12 months, respectively. Concurrently serum DHEA-S levels decreased (P < 0.001) from 245.9 ± 196 to 216.2 ± 203.3 and to 169.7 ± 121.1 µg/dl at 3 and 12 months, respectively. These effects were reversed in 19 patients who discontinued treatment and were re-demonstrated after therapy resumption. Among the 22 surgically treated patients with normal HPA, peri-operative PRL levels decreased rapidly (P < 0.001) with a parallel decline in serum DHEA-S levels (P = 0.03). Strong correlations were noted between PRL and DHEA-S decrements observed with medical or surgical therapy. Medically (n = 21) and surgically (n = 4) patients with impaired HPA function had very low DHEA-S values that were unchanged despite marked reductions in PRL secretion. CONCLUSION: Hyperprolactinemia is associated with a reproducible and reversible increase in serum DHEA-S that was observed in medically- and surgically-treated patients with normal HPA function. Thus, a normal age- and gender-adjusted serum DHEA-S level continues to imply normal HPA function even among hyperprolactinemic subjects.

Lung Metastasis in Pediatric Thyroid Cancer: Radiological Pattern, Molecular Genetics, Response to Therapy, and Outcome.

Context: Lung metastases are common in pediatric thyroid cancer (TC). We present an analysis of a series of lung metastases in pediatric TC. Patients and Methods: Data from 20 patients (16 females, 4 males; median age, 14.5 years; range 10 to 18 years) were analyzed. The tumors included differentiated TC in 19 patients and poorly differentiated TC in 1 patient. Results: Lung metastasis presented with three distinct radiological patterns: lung uptake on diagnostic radioactive iodine whole body scan (DxWBS) only in 3 patients (15%); lung uptake on DxWBS and CT scan as micrometastases (≤1 cm) in 16 patients (80%); and lung uptake on DxWBS and CT scan as macrometastases (>1 cm) in 1 patient (5%). Iodine-131 therapies were administered to all patients (median, three; range one to eight) with a median cumulative administered activity of 317.5 mCi (range, 109 to 682 mCi). None of the patients achieved a complete response but the biochemical response was substantial. During a median follow-up period of 8.2 years (range, 0.75 to 16.3 years), 1 patient (5%) died, 1 patient (5%) had a biochemically incomplete response, 2 patients (10%) had an indeterminate response, 1 patient (5%) had progressive structural disease, and 14 patients (70%) had stable structural disease. Mutational testing of 10 of 20 tumors revealed only two PIK3CA mutations in a single tumor. Conclusions: Lung metastases are common in pediatric TC and present most frequently with bilateral radioiodine-avid micrometastases. Known single point mutations in adult TC are rare in pediatric TC. The biochemical response to iodine-131 can be substantial but resolution of structural abnormalities is rare.

Absence of EIF1AX, PPM1D, and CHEK2 mutations reported in Thyroid Cancer Genome Atlas (TCGA) in a large series of thyroid cancer.

INTRODUCTION: The Thyroid Cancer Genome Atlas (TCGA) was a major project that significantly clarified the key underlying genetic aberrations in papillary thyroid cancer. It confirmed the previously known somatic mutations and gene fusions and disclosed additional genetic alterations that were previously unknown. Among the most significant novel genetic mutations were those in EIF1AX, PPM1D, and CHEK2. OBJECTIVES: We sought to determine the rates of these novel genetic alterations in a large sample of our patients to test the prevalence, reproducibility, and significance of these findings. PATIENTS AND METHODS: We studied thyroid cancer (TC) tumor tissues from 301 unselected patients using polymerase chain reaction (PCR) and direct Sanger sequencing. DNA was isolated from paraffin-embedded formalin-fixed tumor tissue. Exons and exon-intron boundaries harboring the previously reported mutations in TCGA were amplified using PCR and directly sequenced. RESULTS: We found only one of the 301 tumors (0.3%) harboring A113_splice site mutation at the intron 5/exon 6 splice site of EIF1AX gene. Apart from this single mutation, none of the 301 tumors harbored any of the previously reported mutations in any of the three genes, EIF1AX, PPM1D, and CHEK2. A number of previously reported single nucleotide polymorphisms (SNP) were found in CHEK2, PPM1D but not in EIF1AX. These include CHEK2 SNPs, rs375130261, rs200928781, rs540635787, rs142763740, and rs202104749. The PPM1D SNPs rs771831676 and rs61757742 were present in 1.49% and 0.74%, respectively. Each of these SNPs was present in a heterozygous form in 100% of the tumors. An additional analysis of these samples for the most frequently reported mutations in DTC such as BRAFV600E, TERT promoter, and RAS showed a prevalence of 38.87% (117/301), 11.96% (36/301), and 7.64% (23/301), respectively. CONCLUSIONS: Except for a rare A113_splice site mutation in EIF1AX, other recently described somatic mutations in EIF1AX, PPM1D, and CHEK2 were absent in this large series of patients with TC from a different racial group (Saudi Arabia). This might be related to the different techniques used (PCR and direct sequencing) or low density of the mutants. It might also reflect racial differences in the rate of these mutations.