Maria Adelaide Albergaria Pereira

Pheochromocytoma : Study of 50 cases

PURPOSE We studied the clinical picture, sensitivity of the biochemical tests and imaging studies, pathological findings, surgical results and followup of patients with pheochromocytoma. MATERIALS AND METHODS The records of 50 patients with pheochromocytoma were identified. Hyperadrenergic symptoms and signs; urinary dopamine, epinephrine, norepinephrine and vanillylmandelic acid levels; serum dopamine, epinephrine and norepinephrine levels; ultrasonography; computerized tomography; magnetic resonance imaging and 131iodine-metaiodobenzylguanidine images were analyzed. The size, weight and malignancy of the tumors, as well as the operative mortality, survival rate and clinical condition of the patients were also studied. RESULTS The hyperadrenergic syndrome alone was found in 90% of the patients, Cushings syndrome alone in 2%, both syndromes in 4%, a palpable abdominal tumor only in 2% and incidental tumors in 2%. The sensitivities of the urinary evaluation in the diagnosis were metanephrines 97%, vanillylmandelic acid 90%, epinephrine 64%, norepinephrine 93% and dopamine 66%. For serum assessment the sensitivities were epinephrine 67%, norepinephrine 93% and dopamine 63%. The sensitivities of the localization examinations were 89, 94, 100 and 88% for ultrasonography, computerized tomography, magnetic resonance imaging and 131I-metaiodobenzylquanidine, respectively. There was only 1 operative death. Of the patients with benign tumors 88% were cured and 12% remained hypertensive with no clinical or biochemical evidence of a hyperadrenergic profile. Of the 8 patients with malignant pheochromocytoma 1 was lost to followup and 3 died of widespread disease (1 without surgery and at 2, 24 and 78 months postoperatively). Of the 4 living patients 3 had no evidence of disease and 1 was well, although with pulmonary metastases.

In vivo and in vitro oncogenic effects of HIF2A mutations in pheochromocytomas and paragangliomas

Pheochromocytomas and paragangliomas are highly vascular tumors of the autonomic nervous system. Germline mutations, including those in hypoxia-related genes, occur in one third of the cases, but somatic mutations are infrequent in these tumors. Using exome sequencing of six paired constitutive and tumor DNA from sporadic pheochromocytomas and paragangliomas, we identified a somatic mutation in the HIF2A (EPAS1) gene. Screening of an additional 239 pheochromocytomas/paragangliomas uncovered three other HIF2A variants in sporadic (4/167, 2.3%) but not in hereditary tumors or controls. Three of the mutations involved proline 531, one of the two residues that controls HIF2α stability by hydroxylation. The fourth mutation, on Ser71, was adjacent to the DNA binding domain. No mutations were detected in the homologous regions of the HIF1A gene in 132 tumors. Mutant HIF2A tumors had increased expression of HIF2α target genes, suggesting an activating effect of the mutations. Ectopically expressed HIF2α mutants in HEK293, renal cell carcinoma 786-0, or rat pheochromocytoma PC12 cell lines showed increased stability, resistance to VHL-mediated degradation, target induction, and reduced chromaffin cell differentiation. Furthermore, mice injected with cells expressing mutant HIF2A developed tumors, and those with Pro531Thr and Pro531Ser mutations had shorter latency than tumors from mice with wild-type HIF2A. Our results support a direct oncogenic role for HIF2A in human neoplasia and strengthen the link between hypoxic pathways and pheochromocytomas and paragangliomas.

Ectopic ACTH syndrome

Ectopic ACTH syndrome represents a cancer-induced amplification of a property [proopiomelanocortin (POMC) peptides production] normally present in the cells from which the cancer originated but with aberrant posttranslational processing of POMC resulting in a greatly elevated secretion of ACTH precursors. The classic ectopic ACTH-producing tumors described in the 1960s were highly malignant but more recently slowly growing tumors such as carcinoids are reported with increasing frequency. Clinical features of patients with ectopic ACTH were analyzed, including biochemical abnormalities, plasma ACTH, cortisol and urinary steroids. Dynamic tests such as high-dose dexamethasone suppression, metyrapone and ovine-CRH (oCRH) stimulation were explored, as well as inferior petrosal sinus ACTH sampling before and after oCRH. Among the tumor markers examined, elevation of ACTH precursors was uniformly present followed by increased output of calcitonin, gut hormones, oncofetal and placental hormones in decreasing order. Since more than 90% of ectopic ACTH tumors are neuroendocrine in nature exhibiting APUD characteristics, their 2 markers, neuron-specific enolase and chromogranins are very useful. The imaging procedures for localization of the tumor ranged from chest X-rays to computed tomography and magnetic resonance of the chest and abdomen. Abdominal ultrasonography was also useful. Finally somatostatin receptor scintigraphy permitted demonstration of unrecognized tumors and/or metastases, even when the tumors were occult. The ACTH content, immunostaining for APUD markers and altered POMC processing were evaluated in ectopic tumors and/or metastases. Occult ectopic ACTH syndrome of more than 4-6 months of symptoms without the emergence of an obvious source was reviewed. Since the tumors are often clinically and biochemically undistinguishable from pituitary-dependent Cushings disease, inferior petrosal sinus sampling for ACTH after oCRH stimulation established the diagnosis in over 90% of the cases. 60% of the occult tumors were thoracic carcinoids (3/4 bronchial carcinoids), followed by small cell lung cancer and pancreatic neuroendocrine tumors. In 12% the primary etiology was not detected. The rare syndrome of ectopic CRH syndrome (6 published cases) leading to excessive stimulation of the pituitary which became hyperplastic and secreted excessive amounts of ACTH is discussed. Finally, the 12 published cases and 1 unreported patient with ectopic CRH-ACTH tumors were reviewed, the majority being metastatic small cell lung carcinomas, bronchial and thymic carcinoids.

ARMC5 Mutations Are a Frequent Cause of Primary Macronodular Adrenal Hyperplasia

CONTEXT Primary macronodular adrenal hyperplasia (PMAH) is a rare cause of Cushings syndrome, usually characterized by functioning adrenal macronodules and increased cortisol production. Familial clustering of PMAH has been described, suggesting an inherited genetic cause for this condition. OBJECTIVE The aim of the present study was to identify the gene responsible for familial PMAH. PATIENTS AND METHODS Forty-seven individuals of a Brazilian family with PMAH were evaluated. A single-nucleotide polymorphism-based genome-wide linkage analysis followed by whole-exome sequencing were then performed in selected family members. Additionally, 29 other patients with PMAH and 125 randomly selected healthy individuals were studied to validate the genetic findings. Moreover, PMAH tissue was also analyzed through whole-exome sequencing, conventional sequencing, and microsatellite analysis. RESULTS A heterozygous germline variant in the ARMC5 gene (p.Leu365Pro) was identified by whole-exome sequencing in a candidate genomic region (16p11.2). Subsequently, the same variant was confirmed by conventional sequencing in all 16 affected family members. The variant was predicted to be damaging by in silico methods and was not found in available online databases or in the 125 selected healthy individuals. Seven additional ARMC5 variants were subsequently identified in 5 of 21 patients with apparently sporadic PMAH and in 2 of 3 families with the disease. Further molecular analysis identified a somatic mutational event in 4 patients whose adrenal tissue was available. CONCLUSIONS Inherited autosomal dominant mutations in the ARMC5 gene are a frequent cause of PMAH. Biallelic inactivation of ARMC5 is consistent with its role as a potential tumor suppressor gene.

A study of patients with Nelson's syndrome

The prevalence of Nelsons syndrome has varied greatly, at least in part because of the variability of the diagnostic criteria employed by different authors. We define Nelsons syndrome as the presence of an enlarging pituitary tumour associated with elevated fasting plasma ACTH levels and hyperpigmentation in patients with Cushings disease after bilateral adrenalectomy. We have compared patients with Cushings disease who developed Nelsons syndrome after bilateral adrenalectomy with those who did not. Our objective was to find differences between the two groups which might predict the development of Nelsons syndrome.

The role of desmopressin in bilateral and simultaneous inferior petrosal sinus sampling for differential diagnosis of ACTH-dependent Cushing's syndrome

Objective   Bilateral inferior petrosal sinus sampling (BIPSS) with corticotrophin‐releasing hormone (CRH) stimulation is currently the gold standard test for the differential diagnosis of ACTH‐dependent Cushings syndrome. Reports on the use of desmopressin in this approach are limited. The aim of this study was to evaluate the use of desmopressin during BIPSS in a cohort of patients with ACTH‐dependent Cushings syndrome.

Novel MEN1 germline mutations in Brazilian families with multiple endocrine neoplasia type 1.

Objective  To characterize clinical features and identify MEN1 germline mutations in Brazilian families with multiple endocrine neoplasia type 1 (MEN1).

Penetrance of functioning and nonfunctioning pancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1 in the second decade of life.

CONTEXT Data are scarce on the penetrance of multiple endocrine neoplasia type 1 (MEN1)-related nonfunctioning pancreatic neuroendocrine tumors (NF-PETs) and insulinomas in young MEN1 patients. A potential positive correlation between tumor size and malignancy (2-3 cm, 18%; >3 cm, 43%) has greatly influenced the management of MEN1 adults with NF-PETs. OBJECTIVE The aim of the study was to estimate the penetrance of NF-PETs, insulinomas, and gastrinomas in young MEN1 carriers. DESIGN The data were obtained from a screening program (1996-2012) involving 113 MEN1 patients in a tertiary academic reference center. PATIENTS Nineteen MEN1 patients (aged 12-20 y; 16 patients aged 15-20 y and 3 patients aged 12-14 y) were screened for NF-PETs, insulinomas, and gastrinomas. METHODS Magnetic resonance imaging/computed tomography and endoscopic ultrasound (EUS) were performed on 10 MEN1 carriers, magnetic resonance imaging/computed tomography was performed on five patients, and four other patients underwent an EUS. RESULTS The overall penetrance of PETs during the second decade of life was 42% (8 of 19). All eight PET patients had NF-PETs, and half of those tumors were multicentric. One-fifth of the screened patients (21%; 4 of 19) harbored at least one large tumor (>2.0 cm). Insulinoma was detected in two NF-PET patients (11%) at the initial screening; gastrinoma was not present in any cases. Six of the 11 (54%) screened patients aged 15-20 years who underwent an EUS had NF-PETs. Potential false-positive EUS results were excluded based on EUS-guided biopsy results, the reproducibility of the NF-PET findings, or the observation of increased tumor size during follow-up. Distal pancreatectomy and the nodule enucleation of pancreatic head tumors were conducted on three patients with large tumors (>2.0 cm; T2N0M0) that were classified as grade 1 neuroendocrine tumors (Ki-67<2%). CONCLUSIONS Our data demonstrated high penetrance of NF-PETs in 15- to 20-year-old MEN1 patients. The high percentage of the patients presenting consensus criteria for surgery for NF-PET alone or NF-PET/insulinoma suggests a potential benefit for the periodic surveillance of these tumors in this age group.

Role for postoperative cortisol response to desmopressin in predicting the risk for recurrent Cushing's disease

In the early postoperative period of Cushings disease patients, desmopressin may stimulate ACTH secretion in the remnant corticotrophic tumour, but not in nontumour suppressed cells.

Serpin Peptidase Inhibitor Clade A Member 1 as a Potential Marker for Malignancy in Insulinomas

Purpose: The biological behavior of insulinomas cannot be predicted based on histopathologic criteria in which the diagnosis of malignancy is confirmed by the presence of metastases. In this study, microarray and quantitative real-time reverse transcription-PCR were applied to identify differentially expressed genes between malignant and nonmalignant insulinomas to search for useful biomarkers to recognize the metastatic potential of insulinomas. Experimental Design: CodeLink human bioarrays were used to analyze differences in ∼20,000 genes between six well-differentiated endocrine tumors of benign behavior compared with one well-differentiated endocrine carcinoma (WDEC) and three metastases of endocrine carcinomas (MEC). Quantitative real-time reverse transcription-PCR was used to validate differential expressions of five genes in a series of 35 sporadic insulinomas. Serpin peptidase inhibitor clade A member 1 (SERPINA1; α-1-antitrypsin) expression, identified as up-regulated in malignant insulinomas, was also evaluated by immunohistochemistry. Results: Analysis of microarray data resulted in 230 differentially expressed genes. Gene Ontology analysis identified serine-type endopeptidase activity and serine-type endopeptidase inhibitor activity as pathways presenting significant differential expression. Protease serine 2 and complement factor B (from serine-type endopeptidase activity pathway) were respectively confirmed as up-regulated in well-differentiated endocrine tumors of benign behavior (WDET) and in WDEC/MEC. Angiotensinogen and SERPINA1 (from serine-type endopeptidase inhibitor activity pathway) were confirmed as up-regulated in WDEC/MEC. SERPINA1 was shown to be expressed in 85.7% of malignant versus 14.3% of nonmalignant insulinomas by immunohistochemistry. Conclusions: Our data are consistent to the possibility that SERPINA1 is a marker of malignancy in insulinomas. Given the widespread availability of antibody anti-α-1-antitrypsin in pathology services, SERPINA1 expression evaluation might be of clinical utility in recognizing patients more likely to develop an aggressive presentation.