Prognostic factors and mitotane treatment of adrenocortical cancer. Two decades of experience from an institutional case series.

Objectives: This study aimed to characterise the clinicopathological features and prognostic factors of a large cohort of Hungarian patients with adrenocortical cancer diagnosed between 2000-2021. Patients and methods: This retrospective study included seventy-four patients (27 men and 47 women) with histologically confirmed adrenocortical cancer in a single tertiary referral endocrine centre. Descriptive statistics were performed, providing summaries of selected clinical and pathological parameters. Clinicopathological factors contributing to overall survival were analysed. Results: The median age of patients was 48,5 years (17-84 years) at diagnosis. The majority of cases were diagnosed at ENSAT stage II (39,2%) and stage IV (33,8%). At diagnosis, the median tumour size was 9,0 cm (4,5-20 cm). In 47 patients (71,6%), the tumour was hormonally active. The median overall survival and the 5-year survival rate were 23,5 months (95% CI, 17-30,5 months) and 18,3%, respectively. Primary tumour resection was performed in 68 patients (91,8%); R0 surgical resection was achieved in 30 patients. In univariate Cox regression model, tumours with stages III and IV, high proliferative activity (Ki67-index > 10%), R1-R2 surgical resection state and hormonal activity were associated with poorer survival. Cortisol excess, both isolated and combined with androgen production, was associated with poorer survival. Fifty-five patients were treated with mitotane. The overall survival of patients achieving therapeutic mitotane plasma concentration was significantly better compared to those who never reached it [27.0 (2-175) months vs 18.0 (2-83) months; p<0.05)]. The median age, the distribution of gender, ENSAT stage, resection state and Ki67-index did not differ between these two groups. The time needed to reach the therapeutic range of serum mitotane was 96.5 days (95% CI, 75-133 days). Conclusion: Our results confirm previous data that disease stage, mitotic activity, the resection state and the mitotane treatment achieving therapeutic concentration are the most critical parameters influencing the prognosis of adrenocortical cancer. Our data suggest that hormonal activity may be more frequent than described previously, and it is a strong and independent prognostic factor of overall survival. To our knowledge, this is the first single-centre study confirming the prognostic importance of achieving therapeutic mitotane concentration.

Targeted Mutational Profiling and a Powerful Risk Score as Additional Tools for the Diagnosis of Papillary Thyroid Cancer.

Nowadays, the complementary diagnostics based on the suspicious thyroid lesion specific mutational state analysis is indispensable in the clinical practice. We aimed to test and validate our novel 568-mutational hotspot panel (23 cancer-related genes) on papillary thyroid cancers (PTCs) and their tumor-free pairs to find the most powerful mutation pattern related to PTC. The sequencing method was carried on with Ion Torrent PGM on 67 thyroid tissue samples. The most commonly detected mutation was the BRAF c.1799 T > A in all non-classical PTC cases. We utilized a multivariate statistical method (CVA) to determine a discrimination score based on mutational data array and to assess malignancy risk. Based on variants, the BRAF gene has by far the highest indicative power, followed by TSHR and APC. We highlighted novel aspects of the mutational profile and genetic markers of PTC. CVA has correctly assigned most of the samples based on the mutation frequencies and different variables of the selected genes, with high analytical probabilities. The final goal is to set up a new comprehensive rule-in and rule-out test to support the clinical decision making mainly in inconclusive fine-needle aspiration biopsy cases.

PREDICTIVE VALUE OF SOMATIC MUTATIONS FOR THE DEVELOPMENT OF MALIGNANCY IN THYROID NODULES BY CYTOPATHOLOGY.

OBJECTIVE: The purpose of our prospective longitudinal study was to evaluate the predictive efficacy of genetic testing for malignancies in fine-needle aspiration biopsy samples that are cytologically benign at the time of biopsy. METHODS: A total of 779 aspirated cytological samples collected from thyroid nodules of 626 patients were included in a 3-year follow-up study. Consecutive patients with cytologically benign thyroid nodules by the Bethesda System for Reporting Thyroid Cytopathology were enrolled in the study. At enrollment, somatic 1-point nucleotide polymorphisms of BRAF and RAS family genes were tested by melting-point analysis, while RET/PTC and PAX8/PPAR-gamma rearrangements were examined by real-time polymerase chain reaction. The genetic test was considered to be positive if a somatic mutation was found. Malignant cytopathologic diagnoses were confirmed by histopathology. RESULTS: In samples collected from 779 thyroid nodules, there were 39 BRAF, 33 RAS mutations, and 1 RET/PTC rearrangements found at the beginning of the study. No PAX8/PPAR-gamma rearrangement was identified. There were 52 malignant thyroid tumors removed during follow-up, out of which 24 contained a somatic mutation. The specificity of the presence of somatic mutations for malignancies was as high as 93.3%, and sensitivity was 46.2%. The negative predictive value of genetic testing reached 96.0%. CONCLUSION: Our results show that our set of genetic tests can predict the appearance of malignancy in benign thyroid nodules (at the beginning of follow-up) with high specificity and strong negative predictive value. ABBREVIATIONS: BRAF = v-raf murine sarcoma viral oncogene homolog B1 FLUS = follicular lesion of undetermined significance FNAB = fine-needle aspiration biopsy FTC = follicular thyroid carcinoma HRAS = homologous to the oncogene from the Harvey rat sarcoma virus KRAS = homologous to the oncogene from the Kirsten rat sarcoma virus NRAS = first isolated from a human neuroblastoma/neuroblastoma RAS = viral oncogene homolog PAX8 = paired box 8 PCR = polymerase chain reaction PPAR-gamma = peroxisome proliferator-activated receptor gamma PTC = papillary thyroid carcinoma RAS = rat sarcoma RET = rearranged during transfection tyrosine-kinase proto-oncogene SM = somatic mutation SNP = single-nucleotide polymorphism.

Genetic Alterations in Hungarian Patients with Papillary Thyroid Cancer.

The incidence of thyroid cancers is increasing worldwide. Some somatic oncogene mutations (BRAF, NRAS, HRAS, KRAS) as well as gene translocations (RET/PTC, PAX8/PPAR-gamma) have been associated with the development of thyroid cancer. In our study, we analyzed these genetic alterations in 394 thyroid tissue samples (197 papillary carcinomas and 197 healthy). The somatic mutations and translocations were detected by Light Cycler melting method and Real-Time Polymerase Chain Reaction techniques, respectively. In tumorous samples, 86 BRAF (44.2%), 5 NRAS (3.1%), 2 HRAS (1.0%) and 1 KRAS (0.5%) mutations were found, as well as 9 RET/PTC1 (4.6%) and 1 RET/PTC3 (0.5%) translocations. No genetic alteration was seen in the non tumorous control thyroid tissues. No correlation was detected between the genetic variants and the pathological subtypes of papillary cancer as well as the severity of the disease. Our results are only partly concordant with the data found in the literature.

Analysis of circulating microRNAs in adrenocortical tumors.

Differential diagnosis of adrenocortical adenoma (ACA) and carcinoma is of pivotal clinical relevance, as the prognosis and clinical management of benign and malignant adrenocortical tumors (ACTs) is entirely different. Circulating microRNAs (miRNAs) are promising biomarker candidates of malignancy in several tumors; however, there are still numerous technical problems associated with their analysis. The objective of our study was to investigate circulating miRNAs in ACTs and to evaluate their potential applicability as biomarkers of malignancy. We have also addressed technical questions including the choice of profiling and reference gene used. A total of 25 preoperative plasma samples obtained from patients with ACAs and carcinomas were studied by microarray and quantitative real-time PCR. None of the three miRNAs (hsa-miR-192, hsa-mir-197 and hsa-miR-1281) found as differentially expressed in plasma samples in our microarray screening could be validated by quantitative real-time PCR. In contrast, of the selected eight miRNAs reported in the literature as differentially expressed in ACT tissues, five (hsa-miR-100, hsa-miR-181b, hsa-miR-184, hsa-miR-210 and hsa-miR-483-5p) showed a statistically significant overexpression in adrenocortical cancer vs adenoma when normalized on hsa-miR-16 as a reference gene. Receiver operator characteristic analysis of data revealed that the combination of dCThsa-miR-210 - dCThsa-miR-181b and dCThsa-miR-100/dCThsa-miR-181b showed the highest diagnostic accuracy (area under curve 0.87 and 0.85, respectively). In conclusion, we have found significant differences in expression of circulating miRNAs between ACAs and carcinomas, but their diagnostic accuracy is not yet high enough for clinical application. Further studies on larger cohorts of patients are needed to assess the diagnostic and prognostic potential application of circulating miRNA markers.

[Comparative study of somatic oncogene mutations in normal thyroid tissues and thyroid neoplasms]. / Szomatikus onkogén mutációk összehasonlító vizsgálata egészséges és tumoros pajzsmirigy-szövetmintákban.

It is established that numerous somatic oncogene mutation (BRAF, NRAS, HRAS, KRAS) and gene translocations (RET/PTC, PAX8/PPAR-gamma) are associated with the development of thyroid cancer. In this study 22 intraoperative thyroid tissue samples (11 pathologic and 11 normal) were examined. Somatic single nucleotide polymorphisms were analyzed by LigthCycler melting method, while translocations were identified by real-time polymerase chain reaction technique. In tumorous sample 3 BRAF, 2 NRAS and one HRAS mutations were found, as well as one RET/PTC1 translocation. Results confirm international data showing that these oncogene mutations and translocations are linked to thyroid cancer. Cytological examination completed with genetic data may support the diagnosis of thyroid malignancies. In addition, genetic alterations may indicate malignant transformation and may become prognostic factors in future.

Diagnostic performance of salivary cortisol and serum osteocalcin measurements in patients with overt and subclinical Cushing's syndrome.

OBJECTIVE: The cut-off value for salivary cortisol measurement for the diagnosis of Cushing's syndrome (CS) may depend both on the severity of the disease and the composition of control group. Therefore, we examined the utility of midnight salivary cortisol measurements in patients who were evaluated for signs and symptoms of CS or because they had adrenal incidentalomas. Because serum osteocalcin (OC) is considered as a sensitive marker of hypercortisolism, we also investigated whether OC could have a role in the diagnosis of CS. PATIENTS AND METHODS: Each of the 151 patients was included into one of the following groups: (A) overt CS (n=23), (B) subclinical CS (n=18), (C) inactive adrenal adenomas (n=40), (D) patients without HPA disturbances (n=70). Patients (C+D) were used as controls. Serum, salivary and urinary cortisol, and OC were measured by electrochemiluminescence immunoassay. RESULTS: Group A had suppressed OC as compared to both group B and group (C+D). Serum and salivary cortisol concentrations showed strong negative correlations with OC in patients with overt CS. The areas under the curves of salivary and serum cortisol at 24:00 h (0.9790 and 0.9940, respectively) serum cortisol after low dose dexamethasone test (0.9930) and OC (0.9220) obtained from ROC analysis for the diagnosis of overt CS were not statistically different. CONCLUSION: This study confirms the usefulness of midnight salivary cortisol measurements in the diagnosis of overt CS in the everyday endocrinological praxis. Our results suggest that OC may have a role in the diagnosis of overt CS.

Expression of glucocorticoid receptor isoforms in human adrenocortical adenomas.

INTRODUCTION: Glucocorticoid receptor (GR) is expressed in the normal human adrenal gland, however, no study has been performed to evaluate the separate expression of alpha- and beta-isoforms (GRalpha and GRbeta) in normal human adrenals and in adrenocortical adenomas. EXPERIMENTAL: GRalpha and GRbeta mRNA expression was examined by quantitative real-time PCR in 31 adrenal tissues including 19 non-functioning adenomas (NFA), 6 cortisol-producing adenomas (CPA) and 6 normal adrenocortical tissues. In addition, the presence and cellular localization of GRalpha and GRbeta proteins in adrenal tissues were studied by immunohistochemistry. RESULTS: Compared to normal adrenocortical tissues, both GRalpha and GRbeta mRNAs were significantly increased in CPA but not in NFA. Using anti-GRalpha antibody a strong nuclear staining was observed in NFA and CPA, and a less remarkable immunoreactivity was detected in some nuclei of normal adrenocortical cells. GRbeta immunostaining was absent in normal adrenal tissues and NFA, while a strong cytoplasmic and nuclear immunoreaction was found in CPA. CONCLUSIONS: Altered expression of GRalpha and GRbeta in CPA raises their possible role in the pathophysiology of these adrenal tumors, although further studies are needed to elucidate the potential significance of these findings.

Intraoperative determination of PTH concentrations in fine needle tissue aspirates to identify parathyroid tissue during parathyroidectomy.

BACKGROUND: Exact tissue identification during parathyroidectomy is essential to successfully cure hyperparathyroidism. PTH level determination from tissue aspirates has been advocated as a "biochemical frozen section" for parathyroid tissue identification. We investigated the sensitivity and specificity of this method in a large cohort of consecutive patients who underwent parathyroidectomy in a tertiary referral center. METHODS: PTH levels of 359 tissue aspirates were measured intraoperatively in 223 consecutive patients from March 2006 to December 2008. Suspected parathyroid and control tissues were aspirated with a standardized technique immediately after their excision. Samples were processed for quick-PTH assay with peripheral blood samples before and after excision. PTH levels from tissue aspirates were correlated with pathological diagnosis. The Mann-Whitney test was used to determine statistical significance (P < 0.05). RESULTS: A total of 255 parathyroid (196 adenoma, 30 hyperplasia, 4 carcinoma, 25 normal parathyroid) and 104 nonparathyroid tissue (88 thyroid, 16 lymph node, thymus, or fat) aspirates were compared. A highly significant difference was found between PTH levels of parathyroid (8,120 +/- 2,711 pg/ml; interquartile range (IQR): 4,949-9,075) and nonparathyroid (0.8 +/- 9.29 pg/ml; IQR: 0.4-1.4) tissue aspirates (P < 0.005). This test is 100% sensitive and 100% specific to identify parathyroid tissue for values >84 pg/ml. Furthermore, PTH levels of pathological parathyroid aspirates (8,169 +/- 2,597; IQR: 5,634-9,109) were higher than that of normal parathyroid aspirates (4,130 +/- 2,952; IQR: 2,569-8,284; P = 0.0011). CONCLUSIONS: PTH level determination from tissue aspirates is a highly reliable, quick, and simple method to differentiate parathyroid and nonparathyroid tissues during parathyroidectomy. This method can obviate frozen sections in patients undergoing surgery for hyperparathyroidism.

Differences in the expression of histamine-related genes and proteins in normal human adrenal cortex and adrenocortical tumors.

Histamine is involved in the pathogenesis of several tumors; however, there are no data on its possible involvement in human adrenocortical tumorigenesis. The expression of genes and proteins involved in the biosynthesis (histidine decarboxylase, HDC), action (histamine receptors: HRH1-HRH4), and metabolism of histamine is largely unknown both in the normal human adrenal cortex and in adrenocortical tumors. In this study, we examined the expression of histamine-related genes and proteins and histamine content in normal adrenal cortex, benign adrenocortical adenomas, and malignant adrenocortical cancer (ACC). Fifteen normal adrenals and 43 tumors were studied. mRNA expression was examined by real time RT-PCR. Western-blotting and immunohistochemistry were used for the study of proteins. Tissue histamine content was determined by enzyme-linked immunosorbent assay. We found that all proteins involved in histamine biosynthesis and action are present both in the normal adrenal cortex and in the tumors studied. HDC expression and histamine content was highest in the normal tissues and lower in benign tumors, whereas it was significantly less in ACCs. HRH3 expression was significantly higher in ACC samples than in the other groups. Adrenocortical tumorigenesis might, thus, be characterized by reduced histamine biosynthesis; furthermore, different adrenocortical tumor subtypes may show unique histamine receptor expression profiles.

Integrative molecular bioinformatics study of human adrenocortical tumors: microRNA, tissue-specific target prediction, and pathway analysis.

MicroRNAs (miRs) are involved in the pathogenesis of several neoplasms; however, there are no data on their expression patterns and possible roles in adrenocortical tumors. Our objective was to study adrenocortical tumors by an integrative bioinformatics analysis involving miR and transcriptomics profiling, pathway analysis, and a novel, tissue-specific miR target prediction approach. Thirty-six tissue samples including normal adrenocortical tissues, benign adenomas, and adrenocortical carcinomas (ACC) were studied by simultaneous miR and mRNA profiling. A novel data-processing software was used to identify all predicted miR-mRNA interactions retrieved from PicTar, TargetScan, and miRBase. Tissue-specific target prediction was achieved by filtering out mRNAs with undetectable expression and searching for mRNA targets with inverse expression alterations as their regulatory miRs. Target sets and significant microarray data were subjected to Ingenuity Pathway Analysis. Six miRs with significantly different expression were found. miR-184 and miR-503 showed significantly higher, whereas miR-511 and miR-214 showed significantly lower expression in ACCs than in other groups. Expression of miR-210 was significantly lower in cortisol-secreting adenomas than in ACCs. By calculating the difference between dCT(miR-511) and dCT(miR-503) (delta cycle threshold), ACCs could be distinguished from benign adenomas with high sensitivity and specificity. Pathway analysis revealed the possible involvement of G2/M checkpoint damage in ACC pathogenesis. To our knowledge, this is the first report describing miR expression patterns and pathway analysis in sporadic adrenocortical tumors. miR biomarkers may be helpful for the diagnosis of adrenocortical malignancy. This tissue-specific target prediction approach may be used in other tumors too.

[Extra-adrenal pheochromocytoma associated to SDHD gene mutation]. / SDHD génmutációhoz társult extraadrenalis phaeochromocytoma.

UNLABELLED: Hereditary paraganglioma/pheochromocytoma syndrome is an autosomal dominantly inherited disease caused by germline mutation of the genes encoding subunits of the mitochondrial succinate dehydrogenase (SDH) enzyme involved in the mitochondrial respiratory chain. The pathogenetic role of SDH gene mutations was first recognized in 2000. Authors present the history of a patient with extra-adrenal pheochromocytoma who represents in Hungary the first genetically confirmed case of hereditary paraganglioma/pheochromocytoma syndrome due to disease-causing mutation of the SDHD gene. Also, the authors review the progress of our knowledge about this syndrome. CASE REPORT: A 33 years-old man was observed with hypertension, increased perspiration and palpitation. Laboratory analysis showed increased urinary catecholamine metabolite excretion, abdominal radiologic imaging revealed a retroperitoneal tumor with 3.5 cm extension located close to the abdominal aorta. After tumor resection the clinical symptoms disappeared. Histological examination of the tumor proved extra-adrenal pheochromocytoma. Although family history was unremarkable, the young age of the patient raised the possibility of a hereditary syndrome. Mutation screening using peripheral blood DNA samples of the patient indicated the presence of c.148-149 insA frameshift mutation of the SDHD gene. Genetic analysis of family members revealed the presence of the same mutation in his asymptomatic father while the mutation was not present in his mother and brother. CONCLUSION: The presented patient represents the first case with hereditary paraganglioma/pheochromocytoma syndrome from Hungary, in whom genetic analysis identified a disease-causing mutation of the SDHD gene. Pedigree analysis was compatible with genomic imprinting which has been demonstrated in many families with this syndrome.

Functional genomics approaches for the study of sporadic adrenal tumor pathogenesis: clinical implications.

Although sporadic adrenal tumors are frequently encountered in the general population their pathogenesis is not well elucidated. The advent of functional genomics/bioinformatics tools enabling large scale comprehensive genome expression profiling should contribute to significant progress in this field. Some studies have already been published describing gene expression profiles of benign and malignant adrenocortical tumors and phaeochromocytomas. Several genes coding for growth factors and their receptors, enzymes involved in steroid hormone biosynthesis, genes related to the regulation of cell cycle, cell proliferation, adhesion and intracellular metabolism have been found to be up- or downregulated in various tumors. Some alterations in gene expression appear so specific for certain tumor types that their application in diagnosis, determination of prognosis and the choice of therapy can be envisaged. In this short review, the authors will present a synopsis of these recent findings that seem to open new perspectives in adrenal tumor pathogenesis, with emphasis on changes in steroidogenic enzyme expression profiles and highlighting possible clinical implications.

[Diagnosis and treatment outcome in primary aldosteronism based on a retrospective analysis of 187 cases]. / A primer aldosteronismus diagnosztikája és a kezelés eredményei 187 beteg adatainak retrospektív elemzése alapján.

INTRODUCTION: Primary aldosteronism is the most common form of mineralocorticoid hypertension. The disease has been described by Jerome W. Conn in 1955; since that time there has been a great progress in the knowledge concerning the prevalence, diagnostics and treatment of the disease. AIMS: The authors retrospectively analyzed the efficacy of diagnostic procedures and the outcome of treatment by the analysis of data of 187 patients with primary aldosteronism examined between 1958 and 2004 at the 2nd Department of Medicine of Semmelweis University. METHODS: The efficacy of different methods used for the diagnosis, the frequency of the different subtypes of primary aldosteronism, as well as the surgical outcomes in patients with surgically treated subtypes of primary aldosteronism were studied. RESULTS: Aldosterone-producing adenoma was detected in more than two thirds of patients (n = 135), whereas idiopathic hyperaldosteronism was found in 46 patients. Other subtypes of primary hyperaldosteronism occurred less frequently (unilateral primary adrenocortical hyperplasia in 5 patients and adrenocortical carcinoma in one patient). For the diagnosis of familial hyperaldosteronism type I, molecular biological studies of the aldosterone-synthase/11beta-hydroxylase gene chimera were carried out in 30 patients but none of them showed the presence of the chimeric gene. When comparing the clinical parameters of patients with aldosterone-producing adenoma and idiopathic hyperaldosteronism, no significant differences were found in the time period between the diagnosis of hypertension and the diagnosis of primary aldosteronism, or in the systolic and diastolic blood pressure values. The mean of the lowest documented serum potassium concentration was slightly lower in patients with aldosterone-producing adenoma (2.8 +/- 0.1 mmol/l) compared to those with idiopathic hyperaldosteronism (3.1 +/- 0.2 mmol/l), but the difference was not significant. Normokalemic primary hyperaldosteronism was found in 7 cases. The ratio of plasma aldosterone concentration (ng/dl) to plasma renin activity (ng/ml/h) was above 20 in all patients with aldosterone-producing adenoma and in all but 5 cases with idiopathic hyperaldosteronism. To confirm the diagnosis and to differentiate the subtypes of primary aldosteronism, the postural test combined with furosemide administration was performed in the majority of patients. When cases showing an elevation of plasma cortisol level during the test were excluded, this test differentiated patients with aldosterone-producing adenoma from those with idiopathic hyperaldosteronism with a sensitivity of 69% and a specificity of 92%. In cases of adrenocortical adenomas not or not clearly detectable by radiological imaging techniques, as well as in cases with bilateral adrenocortical adenomas, selective adrenal vein sampling was performed (n = 55). All but 4 patients with aldosterone-producing adenoma underwent adrenalectomy. Histology and postoperative hormone results confirmed the preoperative diagnosis in all operated patients. After surgery serum potassium concentration returned to normal in all patients showing low serum potassium levels before surgery. Also, the moderate to severe preoperative hypertension disappeared or improved after surgery. CONCLUSIONS: These observations are in contrast with the results of international studies which showed a high frequency of normokalemic primary aldosteronism and a more frequent occurrence of idiopathic hyperaldosteronism well treatable with aldosterone-antagonists. Therefore, it can be presumed that a significant number of primary aldosteronism cases that are not accompanied with severe hypokalemia remain undetected in Hungary.

[Surgery of primary hyperparathyroidism]. / A primer hyperparathyreosis sebészi kezelése.

Surgery of primary hyperparathyroidism. Primary hyperparathyroidism is usually caused by a single parathyroid adenoma, rarely by multiple adenomas or hyperplasia and in 1-2% of cases by carcinoma. The definitive cure of the disease can be achieved only by surgical means. Unfortunately, only 10% of expected cases based on the number of population are diagnosed in Hungary. The main reason is that the disease has no specific symptoms and it causes only a few cases present with clinical entities such as nephrolithiasis, osteoporosis-osteopenia, pancreatitis, hypertension, peptic ulcer disease, depression, etc. The clue to the diagnosis of primary hyperparathyroidism is usually the laboratory result of hypercalcemia and in order to this aim the measurement of serum Ca would be an obligatory part of routine laboratory investigation in Hungary. The diagnosis of primary hyperparathyroidism rests on the laboratory confirmation of increased serum calcium and inappropriately elevated intact parathyroid hormone concentrations. If surgical intervention is planned, cervical ultrasonography and parathyroid-scintigraphy are indicated for the exact localization of hyperfunctioning parathyroid gland(s). CT and/or MRI are usually not necessary, except in cases of previous neck operation. The operation must be performed by surgeon skilled in parathyroid surgery. The surgical success can be assessed intraoperatively by the use of a gamma probe or by intraoperative measurement of parathyroid hormone concentrations in the serum or in the removed tissue(s). Support of these procedures is recommended. Although many recent publications deal with the minimal invasive methods of parathyroidectomy, the cost-effectiveness of these newer techniques are controversial.

[Clinical symptoms, diagnosis and treatment of multiple endocrine neoplasia type 1. Results of genetic screening in Hungarian patients]. / Az 1-es típusú multiplex endokrin neoplasia klinikai tünetei, diagnózisa és kezelése. A genetikai vizsgálatok hazai tapasztalatai.

Multiple endocrine neoplasia type 1 syndrome is an autosomal dominant disorder characterized by endocrinopathies involving the parathyroid glands, anterior pituitary gland, and pancreas. Also, it may be associated with foregut carcinoid, adrenocortical tumors and non-endocrine tumors. After reviewing the prevalence, genetic background, clinical symptoms, diagnosis and treatment of the disorder, the authors present their genetic screening method used for the detection of mutations of the MEN1 gene (prescreening of polymerase chain reaction amplified exons using temporal temperature gradient gel electrophoresis followed by direct DNA sequencing). Using this method, the authors identified disease-causing MEN1 gene mutations in 9 probands (small deletions in 2 cases, insertion in 2 cases, nonsense mutations in 2 cases and missense mutations in 3 cases). Of the 9 mutations, 4 proved to be novel mutation not reported in the literature. Family screening indicated de novo mutations in 2 probands. In addition to mutations, several sequence polymorphisms were also detected. The authors conclude that one of the major advantages of genetic screening in families with MEN1 syndrome was the identification of family members carrying the mutation who should be regularly screened for disease manifestations and those not carrying the mutation in whom clinical screening is unnecessary. Also, genetic screening may be useful in cases when MEN1 syndrome is suspected, but the clinical manifestations do not fully establish the diagnosis of MEN1 syndrome.

Novel mutation of the CYP17 gene in two unrelated patients with combined 17alpha-hydroxylase/17,20-lyase deficiency: demonstration of absent enzyme activity by expressing the mutant CYP17 gene and by three-dimensional modeling.

The CYP17 gene, located on chromosome 10q24-q25, encodes the cytochrome P450c17 enzyme. Mutations of this gene cause the 17alpha-hydroxylase/17,20-lyase deficiency, which is a rare, autosomal recessive form of congenital adrenal hyperplasia. Approximately 50 different mutations of the CYP17 gene have been described, of which some mutations have been identified in certain ethnic groups. In this study, we present the clinical history, hormonal findings and mutational analysis of two patients from unrelated families, who were evaluated for hypertension, hypokalemia and sexual infantilism. In the first patient, who was a 37-year-old female, additional studies showed a large myelolipoma in the left adrenal gland, and a smaller tumor in the right adrenal gland. In the second patient, who was a 31-year-old phenotypic female, clinical work-up revealed a 46,XY kariotype, absence of ovaries and presence of testes located in the inner opening of both inguinal canals. Analysis of the CYP17 gene by polymerase chain reaction amplification and direct sequencing demonstrated a novel homozygous mutation of codon 440 from CGC (Arg) to TGC (Cys) in both patients. The effect of this novel mutation on 17alpha-hydroxylase/17,20-lyase activity was assessed by in vitro studies on the mutant and wild-type P450c17 generated by site-directed mutagenesis and transfected in nonsteroidogenic COS-1 cells. These studies showed that the mutant P450c17 protein was produced in transfected COS-1 cells, but it had negligible 17alpha-hydroxylase and 17,20-lyase activities. In addition, three-dimensional computerized modeling of the heme-binding site of the P450c17 enzyme indicated that replacement of Arg by Cys at amino acid position 440 predicts a loss of the catalytic activity of the enzyme, as the mutant enzyme containing Cys440 fails to form a hydrogen bond with the propionate group of heme, which renders the mutant enzyme unable to stabilize the proper position of heme. Based on these findings we conclude that expressing the CYP17 gene with functional analysis, combined with three-dimensional computerized modeling of the heme-binding site of the protein provide feasible tools for molecular characterizing of functional consequences of the novel CYP17 mutation on enzyme function.

[New intraoperative diagnostic methods parathyroid surgery. Adenoma localization by gamma probe]. / Uj, intraoperatív diagnosztikus módszerek a mellékpajzsmirigy-sebészetben: gamma-szondás adenoma-lokalizáció.

INTRODUCTION: The key to heal primary hyperparathyroidism is to find the hyper functioning parathyroid gland(s). Promoting this the perioperative isotope guided localization technique is worldwide used in the last years. AIM: Authors use this method since February, 2000. They present their experiences. METHODS: At 122 patients undergoing parathyroidectomy in last 5 years with diagnosis of primary hyperparathyroidism perioperative sestamibi scanning by gamma probe was taken to localize the adenoma. Tc-99m-sestamibi was administered 90-150 minutes before starting anesthesia. The distribution of activity was measured before operation percutaneously on the neck and during operation directly at explored parathyroid regions. Finally the removed specimens were ex vivo scanned. RESULTS: Because of the thyroid lobes also accumulate sestamibi the localizability of adenomas depended on direction of scanning. Important factor is the correct timing of isotope administration in order to achieve domination of parathyroid activity in time of measurement. Localization of adenomas by percutaneous measurement was correct in 36.1% of cases and by perioperative direct scanning in 66.4%. Furthermore, ex vivo scan of removed adenomas showed impressively high activity in all cases. CONCLUSIONS: In their experience sestamibi scanning lightens the operation only in a part of cases but probably it will be the most important method of localization if isotope selectively accumulating in parathyroid gland could be found. For the moment the greatest profit of this method is that the ex vivo measurement indicates the success of operation with great probability.