Malignant struma ovarii with a robust response to radioactive iodine.

SUMMARY: Struma ovarii is a rare, usually benign ovarian tumour with malignancy occurring in <5% of cases. Metastases, particularly seeding to bone, are extremely rare. Presentation is variable but often features local pain and/or ascites and hyperthyroidism may occur. It is not established how to best treat and follow patients with extensive disease. Case reports of radioiodine (I131) ablative therapy following thyroidectomy have shown reduced recurrence. We describe the case of a 33-year-old woman who presented with bone pain and was diagnosed with skeletal metastases with features of follicular thyroid carcinoma. However, thyroid pathology was benign. She recalled that 5 years prior, an ovarian teratoma was excised, classified at that time as a dermoid cyst. Retrospective review of this pathology confirmed struma ovarii without obvious malignant features. The patient was found to have widespread metastases to bone and viscera and her thyroglobulin was >3000 µg/L following recombinant TSH administration prior to her first dose of I131. At 25 months following radioiodine treatment, she is in remission with an undetectable thyroglobulin and clear I131 surveillance scans. This case demonstrates an unusual presentation of malignant struma ovarii together with challenges of predicting metastatic disease, and demonstrates a successful radioiodine regimen inducing remission. LEARNING POINTS: Malignant transformation of struma ovarii (MSO) is extremely rare and even rarer are metastatic deposits in bone and viscera. MSO can be difficult to predict by initial ovarian pathology, analogous to the difficulty in some cases of differentiating between follicular thyroid adenoma and carcinoma. No consensus exists on the management for post operative treatment of MSO; however, in this case, three doses of 6Gbq radioiodine therapy over a short time period eliminated metastases to viscera and bone. Patients should continue to have TSH suppression for ~5 years. Monitoring thyroglobulin levels can predict recurrence.

Destabilizing RET in targeted treatment of thyroid cancers.

Metastatic differentiated thyroid cancers (DTC) are resistant to traditional chemotherapy. Kinase inhibitors have shown promise in patients with progressive DTC, but dose-limiting toxicity is commonplace. HSP90 regulates protein degradation of several growth-mediating kinases such as RET, and we hypothesized that HSP90 inhibitor (AUY922) could inhibit RET-mediated medullary thyroid cancer (MTC) as well as papillary thyroid cancer (PTC) cell growth and also radioactive iodine uptake by PTC cells. Studies utilized MTC cell lines TT (C634W) and MZ-CRC-1 (M918T) and the PTC cell line TPC-1 (RET/PTC1). Cell viability was assessed with MTS assays and apoptosis by flow cytometry. Signaling target expression was determined by western blot and radioiodine uptake measured with a gamma counter. Prolonged treatment of both MTC cell lines with AUY922 simultaneously inhibited both MAPK and mTOR pathways and significantly induced apoptosis (58.7 and 78.7% reduction in MZ-CRC-1 and TT live cells respectively, following 1 µM AUY922; P<0.02). Similarly in the PTC cell line, growth and signaling targets were inhibited, and also a 2.84-fold increase in radioiodine uptake was observed following AUY922 administration (P=0.015). AUY922 demonstrates in vitro activity against MTC and PTC cell lines. We observed a potent dose-dependent increase in apoptosis in MTC cell lines following drug administration confirming its anti-tumorigenic effects. Western blots confirm inhibition of pro-survival proteins including AKT suggesting this as the mechanism of cell death. In a functional study, we observed an increase in radioiodine uptake in the PTC cell line following AUY922 treatment. We believe HSP90 inhibition could be a viable alternative for treatment of RET-driven chemo-resistant thyroid cancers.

Structural and functional consequences of succinate dehydrogenase subunit B mutations.

Mitochondrial dysfunction, due to mutations of the gene encoding succinate dehydrogenase (SDH), has been implicated in the development of adrenal phaeochromocytomas, sympathetic and parasympathetic paragangliomas, renal cell carcinomas, gastrointestinal stromal tumours and more recently pituitary tumours. Underlying mechanisms behind germline SDH subunit B (SDHB) mutations and their associated risk of disease are not clear. To investigate genotype-phenotype correlation of SDH subunit B (SDHB) variants, a homology model for human SDH was developed from a crystallographic structure. SDHB mutations were mapped, and biochemical effects of these mutations were predicted in silico. Results of structural modelling indicated that many mutations within SDHB are predicted to cause either failure of functional SDHB expression (p.Arg27*, p.Arg90*, c.88delC and c.311delAinsGG), or disruption of the electron path (p.Cys101Tyr, p.Pro197Arg and p.Arg242His). GFP-tagged WT SDHB and mutant SDHB constructs were transfected (HEK293) to determine biological outcomes of these mutants in vitro. According to in silico predictions, specific SDHB mutations resulted in impaired mitochondrial localisation and/or SDH enzymatic activity. These results indicated strong genotype-functional correlation for SDHB variants. This study reveals new insights into the effects of SDHB mutations and the power of structural modelling in predicting biological consequences. We predict that our functional assessment of SDHB mutations will serve to better define specific consequences for SDH activity as well as to provide a much needed assay to distinguish pathogenic mutations from benign variants.

Mortality associated with primary hyperparathyroidism.

561 patients with primary hyperparathyroidism were followed between 1961 and 1994. Relative survival was compared to that of the Australian population studied during the same time interval. Mortality was significantly greater in the hyperparathyroid population (P<0.001). Mortality was not greater in the patients with serum calcium levels >3.00 mmol/L compared to those with a serum calcium levels <3.00 mmol/L. 113 patients did not have parathyroid surgery. Their relative survival was not significantly different from those who had surgery but their mean serum calcium and parathyroid hormone (PTH) levels were significantly lower than those who had surgery. A re-analysis of the 453 patients followed between 1972 and 2011 was carried out and a 20-year survival analysis made of those diagnosed between 1972 and 1981 and those diagnosed between 1982 and 1991. The latter group had significantly worse relative mortality than the former group (P<0.001) but was significantly older at the time of diagnosis (56.94 ± 14.83 vs 52.01 ± 13.58, P<0.001). The serum calcium and serum PTH levels were not significantly different between these two groups.

Long noncoding RNA profiles of adrenocortical cancer can be used to predict recurrence.

Adrenocortical carcinoma (ACC) is an aggressive malignancy with high rates of recurrence following surgical resection. Long noncoding RNAs (lncRNAs) play an important role in cancer development. Pathogenesis of adrenal tumours have been characterised by mRNA, microRNA and methylation expression signatures, but it is unknown if this extends to lncRNAs. This study describes lncRNA expression signatures in ACC, adrenal cortical adenoma (ACA) and normal adrenal cortex (NAC) and presents lncRNAs associated with ACC recurrence to identify novel prognostic and therapeutic targets. RNA was extracted from freshly frozen tissue with confirmation of diagnosis by histopathology. Focused lncRNA and mRNA transcriptome analysis was performed using the ArrayStar Human LncRNA V3.0 microarray. Differentially expressed lncRNAs were validated using quantitative reverse transcriptase-PCR and correlated with clinical outcomes. Microarray of 21 samples (ten ACCs, five ACAs and six NACs) showed distinct patterns of lncRNA expression between each group. A total of 956 lncRNAs were differentially expressed between ACC and NAC, including known carcinogenesis-related lncRNAs such as H19, GAS5, MALAT1 and PRINS (P≤0.05); 85 lncRNAs were differentially expressed between ACC and ACA (P≤0.05). Hierarchical clustering and heat mapping showed ACC samples correctly grouped compared with NAC and ACA. Sixty-six differentially expressed lncRNAs were found to be associated with ACC recurrence (P≤0.05), one of which, PRINS, was validated in a group of 20 ACCs and also found to be associated with metastatic disease on presentation. The pathogenesis of adrenal tumours extends to lncRNA dysregulation and low expression of the lncRNA PRINS is associated with ACC recurrence.

Succinate dehydrogenase subunit D and succinate dehydrogenase subunit B mutation analysis in canine phaeochromocytoma and paraganglioma.

Phaeochromocytomas (PCs) are tumours of the adrenal medulla chromaffin cells. Paragangliomas (PGLs) arise in sympathetic ganglia (previously called extra-adrenal PCs) or in non-chromaffin parasympathetic ganglia cells that are usually non-secretory. Parenchymal cells from these tumours have a common embryological origin from neural crest ectoderm. Several case series of canine PCs and PGLs have been published and a link between the increased incidence of chemoreceptor neoplasia in brachycephalic dog breeds and chronic hypoxia has been postulated. A similar link to hypoxia in man led to the identification of germline heterozygous mutations in the gene encoding succinate dehydrogenase subunit D (SDHD) and subsequently SDHA, SDHB and SDHC in similar tumours. We investigated canine PCs (n = 6) and PGLs (n = 2) for SDHD and SDHB mutations and in one PGL found a somatic SDHD mutation c.365A>G (p.Lys122Arg) in exon 4, which was not present in normal tissue from this brachycephalic dog. Two PCs were heterozygous for both c.365A>G (p.Lys122Arg) mutation and an exon 3 silent variant c.291G>A. We also identified the heterozygous SDHB exon 2 mutation c.113G>A (p.Arg38Gln) in a PC. These results illustrate that genetic mutations may underlie tumourigenesis in canine PCs and PGLs. The spontaneous nature of these canine diseases and possible association of PGLs with hypoxia in brachycephalic breeds may make them an attractive model for studying the corresponding human tumours.

Overexpression of miR-210 is associated with SDH-related pheochromocytomas, paragangliomas, and gastrointestinal stromal tumours.

miR-210 is a key regulator of response to hypoxia. Pheochromocytomas (PCs) and paragangliomas (PGLs) with germline SDHx or VHL mutations have pseudohypoxic gene expression signatures. We hypothesised that PC/PGLs containing SDHx or VHL mutations, and succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumours (GISTs), would overexpress miR-210 relative to non-SDH or -VHL-mutated counterparts. miR-210 was analysed by quantitative PCR in i) 39 PC/PGLs, according to genotype (one SDHA, five SDHB, seven VHL, three NF1, seven RET, 15 sporadic, one unknown) and pathology (18 benign, eight atypical, 11 malignant, two unknown); ii) 18 GISTs, according to SDHB immunoreactivity (nine SDH-deficient and nine SDH-proficient) and iii) two novel SDHB-mutant neurosphere cell lines. miR-210 was higher in SDHx- or VHL-mutated PC/PGLs (7.6-fold) compared with tumours without SDHx or VHL mutations (P=0.0016). miR-210 was higher in malignant than in unequivocally benign PC/PGLs (P=0.05), but significance was lost when benign and atypical tumours were combined (P=0.08). In multivariate analysis, elevated miR-210 was significantly associated with SDHx or VHL mutation, but not with malignancy. In GISTs, miR-210 was higher in SDH-deficient (median 2.58) compared with SDH-proficient tumours (median 0.60; P=0.0078). miR-210 was higher in patient-derived neurosphere cell lines containing SDHB mutations (6.5-fold increase) compared with normal controls, in normoxic conditions (P<0.01). Furthermore, siRNA-knockdown of SDHB in HEK293 cells increased miR-210 by 2.7-fold (P=0.001) under normoxia. Overall, our results suggest that SDH deficiency in PC, PGL and GISTs induces miR-210 expression and substantiates the role of aberrant hypoxic-type cellular responses in the development of these tumours.

Utilization of a MAB for BRAF(V600E) detection in papillary thyroid carcinoma.

Identification of BRAF(V600E) in thyroid neoplasia may be useful because it is specific for malignancy, connotes a worse prognosis, and is the target of novel therapies currently under investigation. Sanger sequencing is the 'gold standard' for mutation detection but is subject to sampling error and requires resources beyond many diagnostic pathology laboratories. In this study, we compared immunohistochemistry (IHC) using a BRAF(V600E) mutation-specific MAB to Sanger sequencing on DNA from formalin-fixed paraffin-embedded tissue, in a well-characterized cohort of 101 papillary thyroid carcinoma (PTC) patients. For all cases, an IHC result was available; however, five cases failed Sanger sequencing. Of the 96 cases with molecular data, 68 (71%) were BRAF(V600E) positive by IHC and 59 (61%) were BRAF(V600E) positive by sequencing. Eleven cases were discordant. One case was negative by IHC and initially positive by sequencing. Repeat sequencing of that sample and sequencing of a macrodissected sample were negative for BRAF(V600E). Of ten cases positive by IHC but negative by sequencing on whole sections, repeat sequencing on macrodissected tissue confirmed the IHC result in seven cases (suggesting that these were false negatives of sequencing on whole sections). In three cases, repeat sequencing on recut tissue remained negative (including using massive parallel sequencing), but these cases demonstrated relatively low neoplastic cellularity. We conclude that IHC for BRAF(V600E) is more sensitive and specific than Sanger sequencing in the routine diagnostic setting and may represent the new gold standard for detection of BRAF(V600E) mutation in PTC.

Functional estrogen receptor alpha promoter polymorphism is associated with improved endothelial-dependent vasolidation.

Estrogen receptor alpha (ERalpha) mediates beneficial actions on endothelial nitric oxide synthase (eNOS) and cholesterol metabolism. Genetic variations in the promoter of the ERalpha may therefore influence vascular function. We have identified a single nucleotide polymorphism (T>C) in the transcriptional element "ERNE" upstream of ERalpha which abolished the negative effect of this element in luciferase reporter assays and was associated with reduction in LDL cholesterol in a small association study. We have now examined for the association of this putative functional polymorphism with endothelial function. Endothelial-dependent relaxation (EDR) was measured in organ bath preparations of human saphenous vein obtained from 101 individuals (81 males and 20 females) undergoing coronary artery bypass surgery. The presence of the variant C allele was associated with enhanced EDR independently of hypercholesterolaemia, smoking and diabetes, as well as sex (ANOVA for ACh induced relaxation: p=0.033). In males, the presence of the C allele was associated with a 225% augmentation of endothelial-dependent relaxation compared to wild-type (55.5+/-10%; n=3 vs. 24.7+/-1%; n=78; p<0.001). In summary, a polymorphism in the ERalpha negative transcriptional element which results in increased transcription in vitro is associated with substantial augmentation of endothelial-dependent vasorelaxation.

Microarray gene expression and immunohistochemistry analyses of adrenocortical tumors identify IGF2 and Ki-67 as useful in differentiating carcinomas from adenomas.

The management of adrenocortical tumors (ACTs) is complex. The Weiss score is the present most widely used system for ACT diagnosis. An ACT is scored from 0 to 9, with a higher score correlating with increased malignancy. However, ACTs with a score of 3 can be phenotypically benign or malignant. Our objective is to use microarray profiling of a cohort of adrenocortical carcinomas (ACCs) and adrenocortical adenomas (ACAs) to identify discriminatory genes that could be used as an adjunct to the Weiss score. A cohort of Weiss score defined ACCs and ACAs were profiled using Affymetrix HGU133plus2.0 genechips. Genes with high-discriminatory power were identified by univariate and multivariate analyses and confirmed by quantitative real-time reverse transcription PCR and immunohistochemistry (IHC). The expression of IGF2, MAD2L1, and CCNB1 were significantly higher in ACCs compared with ACAs while ABLIM1, NAV3, SEPT4, and RPRM were significantly lower. Several proteins, including IGF2, MAD2L1, CCNB1, and Ki-67 had high-diagnostic accuracy in differentiating ACCs from ACAs. The best results, however, were obtained with a combination of IGF2 and Ki-67, with 96% sensitivity and 100% specificity in diagnosing ACCs. Microarray gene expression profiling accurately differentiates ACCs from ACAs. The combination of IGF2 and Ki-67 IHC is also highly accurate in distinguishing between the two groups and is particularly helpful in ACTs with Weiss score of 3.

Laparoscopic surgery is safe for large adrenal lesions.

INTRODUCTION: Laparoscopic adrenalectomy has surpassed open adrenalectomy as the gold standard for excision of benign adrenal lesions. The size threshold for offering laparoscopic adrenalectomy is controversial as the prevalence of adrenocortical carcinoma increases with increasing tumour size. The aim of this paper was to assess the safety of laparoscopic adrenalectomy for large adrenal tumours (tumours > or = 60 mm). METHODS: A retrospective cohort study of patients who underwent adrenalectomy in a single unit during the period 1995-2005 was undertaken. RESULTS: One hundred and seventy patients with 173 tumours were included in this study. Of these, 29 were > or = 60 mm in size, and 16 of these patients underwent laparoscopic adrenalectomy. There were 8 adrenocortical carcinomas in the group with tumours > or = 60 mm in size. Five of these patients underwent an open adrenalectomy, while 2 and 1 patients had laparoscopic and laparoscopic converted to open adrenalectomy respectively. Four of the patients undergoing open adrenalectomy died of their disease while 1 is alive with recurrence 3 years later. The 3 patients who underwent either laparoscopic or laparoscopic converted to open adrenalectomy are alive without evidence of disease after 18 months follow up. CONCLUSION: Our data show that patients with tumours > or = 60 mm with no preoperative or intraoperative evidence of malignancy can undergo laparoscopic adrenalectomy without evidence of recurrence on short term follow up. These findings are concordant with the growing body of literature supporting laparoscopic adrenalectomy for potentially malignant tumours > or = 60 mm in size without preoperative or intraoperative features of malignancy.

Novel estrogen receptor alpha promoter polymorphism increases ventricular hypertrophic response to hypertension.

Given the strong genetic contribution to blood pressure and left ventricular hypertrophy (LVH), and the influence of estrogen on these parameters, we hypothesized that polymorphisms in the estrogen receptor alpha (ERalpha) promoter may influence LVH. Three novel polymorphisms were identified upstream of the ERalpha alternatively spliced exon 1E, within sequence which demonstrated significant promoter activity in vitro. Demonstration of ERalpha E isoform expression in human ventricle by RT-PCR supported a possible functional role for the 1E novel polymorphisms in estrogen signaling in the heart. Indeed, G>A (-721 E) was significantly associated with LVH after controlling for systolic blood pressure and sex in a healthy population (n=74), contributing to 23% of interventricular septum (IVS) width variance (p<0.001) and 9.4% of left ventricular mass index (LVMI) variance (p=0.035). In a separate hypertensive cohort, male carriers of the A allele (n=8) had a 17% increase in IVS (95% CI: 6-28%) and a 19% increase in LVMI (3-34%) compared to GG homozygotes (n=84). We conclude that a novel polymorphism in the promoter of a cardiac mRNA splice isoform of ERalpha is associated with LVH.

An apparently sporadic paraganglioma with an SDHB gene germline mutation presenting at age 68 years.

Paragangliomas (PGLs) are rare tumours arising from parasympathetic-associated paraganglia (particularly of the head and neck) or from sympathetic-associated paraganglia such as in the adrenal medulla when they are termed phaeochromocytomas and at extra-adrenal sites in the abdomen and thorax. Recent reports have found frequent germline mutations of VHL, RET, SDHB or SDHD not only in familial cases but also in apparently sporadic cases of phaeochromocytoma. These germline mutations are particularly likely to be found if multifocal disease is present or if the phaeochromocytoma or PGL occurs at a young age. We report a germline splice site mutation in SDHB in a patient presenting with an incidental, apparently sporadic, abdominal sympathetic PGL at 68 years of age.

A genome-wide screen in 1119 relative pairs with autoimmune thyroid disease.

CONTEXT: Autoimmune thyroid diseases (AITD), comprising Graves' disease and autoimmune hypothyroidism, are characterized by loss of immunological self-tolerance to thyroid antigens. These are complex diseases arising from a combination of genetic and environmental factors. An understanding of the genetic susceptibility factors for AITD could help to target treatments more effectively and identify people at risk for these conditions. OBJECTIVE: The objective of this study was to identify regions of genetic linkage to AITD that could potentially harbor genetic susceptibility factors for these conditions. DESIGN: The study design was a genome-wide screen performed on affected relative pairs with AITD. SETTING: Patients were recruited through hospital endocrinology clinics. PARTICIPANTS: Some 1119 Caucasian relative pairs affected with AITD (Graves' disease or autoimmune hypothyroidism) were recruited into the study. INTERVENTION: Blood samples were obtained from each participant for DNA analysis, and clinical questionnaires were completed. MAIN OUTCOME MEASURE: The study aimed to identify regions of genetic linkage to AITD. RESULTS: Three regions of suggestive linkage were obtained on chromosomes 18p11 (maximum LOD score, 2.5), 2q36 (maximum LOD score, 2.2), and 11p15 (maximum LOD score, 2.0). No linkage to human leukocyte antigen was found. CONCLUSIONS: The absence of significant evidence of linkage at any one locus in such a large dataset argues that genetic susceptibility to AITD reflects a number of loci, each with a modest effect. Linkage analysis may be limited in defining such loci, and large-scale association studies may prove to be more useful in identifying genetic susceptibility factors for AITD.

Mutation and methylation analysis of TP53 in adrenal carcinogenesis.

AIM: To investigate the role of coding region mutation and promoter hypermethylation of TP53 in adrenocortical cancer formation. METHODS: Twenty sporadic adrenocortical cancers (ACCs) and five normal adrenal tissue samples were available for analysis. Coding region mutation of TP53 in 20 ACCs was examined by polymerase chain amplification using intronic primers for exons 2-11 and direct sequencing of the product. In 10 ACCs and five normal adrenal tissue specimens, methylation of the 16 CpG sites within the TP53 promoter was examined using bisulphite methylation sequencing. RESULTS: Coding region mutation in TP53 was demonstrated in 5 of 20 ACCs. There were four mis-sense mutations and one frameshift mutation. Four of 5 patients with a TP53 mutation had metastases at diagnosis or detected soon thereafter and 3 of 4 died of disease within 12 months of surgical resection. No methylation was seen in the TP53 promoter in 10 ACC and the five normal adrenal tissues examined. CONCLUSION: Coding region mutation in TP53 occurs in 25% of ACCs with a trend toward a poorer prognosis. Promoter methylation of TP53 is not present in ACC as a mechanism for tumour suppressor gene (TSG) inactivation and, therefore, other genes in the 17p13 region are implicated in adrenal carcinogenesis.

Intravenous pamidronate in the treatment and prevention of osteoporosis.

BACKGROUND: Potent oral bisphosphonates are the mainstay of therapy for osteoporosis. However, there are patients who cannot have oral bisphosphonates (e.g. because of gastrointestinal side-effects). Therefore, we wanted to examine the effects of intermittent i.v. pamidronate (APD) on bone mineral density (BMD) in patients who needed bisphosphonate therapy but could not have oral bisphosphonates. AIM: To assess BMD before and after intermittent i.v. APD in patients requiring a bisphosphonate either for the prevention of osteoporosis on concurrent steroid therapy or for the treatment of osteoporosis. METHODS: This was a retrospective audit of 84 consecutive patients at risk of fractures commencing APD between October 1997 and May 2000. Patients were treated with intermittent i.v. APD. BMD as measured by dual-energy X-ray absorptiometry before and after APD was the main outcome. RESULTS: The mean length of treatment and mean total APD dose were 16.8 +/- 7.0 months and 186.1 +/- 79.5 mg respectively. The reasons for using APD were failure to qualify for oral bisphosphonates on the pharmaceutical benefits scheme due to lack of documented minimal trauma fractures (58%), symptomatic gastro--oesophageal disease (20%), intolerance of oral bisphosphonates (18%) and lack of efficacy of calcitriol (4%). Mean baseline T-score at lumbar (L) 2-4 spine and femoral neck were -1.54 +/- 1.22 and - 2.87 +/- 1.19, respectively. From baseline to after APD treatment, there was a significant increase in L2-4 BMD (0.883 +/- 0.175 vs 0.912 +/- 0.176 g/cm(2), P < 0.001, mean increase +3.5%), in femoral neck BMD (0.667 +/- 0.137 vs 0.680 +/- 0.134 g/cm(2), P= 0.001, mean increase +2.1%) and in trochanteric BMD (0.549 +/- 0.129 vs 0.566 +/- 0.132 g/cm(2), P < 0.001, mean increase +3.1%). One-third of the patients were on oral glucocorticoids at the time of the present study and they had a similar increase in BMD compared to patients not on gluco-corticoids. Mild side-effects occurred in seven patients, none of whom discontinued treatment. CONCLUSION: Intermittent APD increases BMD and may be a suitable alternative for patients who cannot have oral bisphosphonates.