Clinical identification of expressed proteins in adrenal medullary hyperplasia detected with hypertension

BACKGROUND

Hypertension remains a challenging public health problem worldwide, and adrenal gland-related diseases are one class of the major causes for secondary hypertension. Among them, one relatively rare pattern is adrenal hyperplastic hypertension caused by adrenal medullary hyperplasia (AMH), leading to excessive secretion of autonomic catecholamine. Given that the pathological changes of adrenal medulla are not well correlated to the onset and even severity of secondary hypertension, the molecular basis why some AMH patients are accompanied with hypertension remains unclear and is worth exploring.

AIMS

For this reason, this study aims at investigating differentially expressed proteins in clinical AMH tissue, with special focus on the potential contribution of these differentially expressed proteins to AMH development, in order to have a better understanding of mechanisms how AMH leads to secondary hypertension to some extent.

METHODS AND RESULTS

To this end, AMH specimens were successfully obtained and verified through computed tomography (CT) and haematoxylin-eosin (HE) staining. Proteomic analyses of AMH and control tissues revealed 782 kinds of differentially expressed proteins. Compared with the control tissue, there were 357 types of upregulated proteins and 425 types of downregulated proteins detected in AMH tissue. Of interest, these differentially expressed proteins were significantly enriched in 60 gene ontology terms (P < 0.05), including 28 biological process terms, 14 molecular function terms, and 18 cellular component terms. Pathway analysis further indicated that 306 proteins exert their functions in at least one Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Western blotting showed enhanced expression of phenylethanolamine N- methyltransferase (PNMT), myelin protein zero (MPZ), and Ras-related protein Rab-3C (RAB3C), and reduced expression of cluster of differentiation 36 (CD36) observed in AMH tissue in comparison with controls.

CONCLUSIONS

Clinical AMH specimens display a different proteomic profile compared to control tissue. Of note, PNMT, MPZ, RAB3C, and CD36 are found to differentially expressed and can be potential targets for AMH, providing a theoretical basis for mechanistic exploration of AMH along with hypertension.

Thyroid Hormone Deficiency Suppresses Fetal Pituitary-Adrenal Function Near Term: Implications for the Control of Fetal Maturation and Parturition

Background: The fetal hypothalamic-pituitary-adrenal (HPA) axis plays a key role in the control of parturition and maturation of organ systems in preparation for birth. In hypothyroid fetuses, gestational length may be prolonged and maturational processes delayed. The extent to which the effects of thyroid hormone deficiency in utero on the timing of fetal maturation and parturition are mediated by changes to the structure and function of the fetal HPA axis is unknown. Methods: In twin sheep pregnancies where one fetus was thyroidectomized and the other sham-operated, this study investigated the effect of hypothyroidism on circulating concentrations of adrenocorticotrophic hormone (ACTH) and cortisol, and the structure and secretory capacity of the anterior pituitary and adrenal glands. The relative population of pituitary corticotrophs and the masses of the adrenal zones were assessed by immunohistochemical and stereological techniques. Adrenal mRNA abundances of key steroidogenic enzymes and growth factors were examined by quantitative polymerase chain reaction. Results: Hypothyroidism in utero reduced plasma concentrations of ACTH and cortisol. In thyroid-deficient fetuses, the mass of corticotrophs in the anterior pituitary gland was unexpectedly increased, while the mass of the zona fasciculata and its proportion of the adrenal gland were decreased. These structural changes were associated with lower adrenocortical mRNA abundances of insulin-like growth factor (IGF)-I and its receptor, and key steroidogenic enzymes responsible for glucocorticoid synthesis. The relative mass of the adrenal medulla and its proportion of the adrenal gland were increased by thyroid hormone deficiency in utero, without any change in expression of phenylethanolamine N-methyltransferase or the IGF system. Conclusions: Thyroid hormones are important regulators of the structure and secretory capacity of the pituitary-adrenal axis before birth. In hypothyroid fetuses, low plasma cortisol may be due to impaired adrenocortical growth and steroidogenic enzyme expression, secondary to low circulating ACTH concentration. Greater corticotroph population in the anterior pituitary gland of the hypothyroid fetus indicates compensatory cell proliferation and that there may be abnormal corticotroph capacity for ACTH synthesis and/or impaired hypothalamic input. Suppression of the development of the fetal HPA axis by thyroid hormone deficiency may contribute to the delay in fetal maturation and delivery observed in hypothyroid offspring.

Single-cell atlas of developing murine adrenal gland reveals relation of Schwann cell precursor signature to neuroblastoma phenotype

Neuroblastoma is the most common extracranial solid tumor and accounts for ∼10% of pediatric cancer-related deaths. The exact cell of origin has yet to be elucidated, but it is generally accepted that neuroblastoma derives from the neural crest and should thus be considered an embryonal malignancy. About 50% of primary neuroblastoma tumors arise in the adrenal gland. Here, we present an atlas of the developing mouse adrenal gland at a single-cell level. Five main cell cluster groups (medulla, cortex, endothelial, stroma, and immune) make up the mouse adrenal gland during fetal development. The medulla group, which is of neural crest origin, is further divided into seven clusters. Of interest is the Schwann cell precursor ("SCP") and the "neuroblast" cluster, a highly cycling cluster that shares markers with sympathoblasts. The signature of the medullary SCP cluster differentiates neuroblastoma patients based on disease phenotype: The SCP signature score anticorrelates with ALK and MYCN expression, two indicators of poor prognosis. Furthermore, a high SCP signature score is associated with better overall survival rates. This study provides an insight into the developing adrenal gland and introduces the SCP gene signature as being of interest for further research in understanding neuroblastoma phenotype.

Case Report: Three Rare Cases of Ectopic ACTH Syndrome Caused by Adrenal Medullary Hyperplasia

Ectopic ACTH syndrome (EAS) accounts for 10-20% of endogenous Cushing's syndrome (CS). Hardly any cases of adrenal medullary hyperplasia have been reported to ectopically secrete adrenocorticotropic hormone (ACTH). Here we describe a series of three patients with hypercortisolism secondary to ectopic production of ACTH from adrenal medulla. Cushingoid features were absent in case 1 but evident in the other two cases. Marked hypokalemia was found in all three patients, but hyperglycemia and osteoporosis were present only in case 2. All three patients showed significantly elevated serum cortisol and 24-h urinary cortisol levels. The ACTH levels ranged from 19.8 to 103.0pmol/L, favoring ACTH-dependent Cushing's syndrome. Results of bilateral inferior petrosal sinus sampling (BIPSS) for case 1 and case 3 confirmed ectopic origin of ACTH. The extremely high level of ACTH and failure to suppress cortisol with high dose dexamethasone suppression test (HDDST) suggested EAS for patient 2. However, image studies failed to identify the source of ACTH secretion. Bilateral adrenalectomy was performed for rapid control of hypercortisolism. After surgery, cushingoid features gradually disappeared for case 2 and case 3. Blood pressure, blood glucose and potassium levels returned to normal ranges without medication for case 2. The level of serum potassium also normalized without any supplementation for case 1 and case 3. The ACTH levels of all three patients significantly decreased 3-6 months after surgery. Histopathology revealed bilateral adrenal medullary hyperplasia and immunostaining showed positive ACTH staining located in adrenal medulla cells. In summary, our case series reveals the adrenal medulla to be a site of ectopic ACTH secretion. Adrenal medulla-originated EAS makes the differential diagnosis of ACTH-dependent Cushing's syndrome much more difficult. Control of the hypercortisolism is mandatory for such patients.

Stem cells, evolutionary aspects and pathology of the adrenal medulla: A new developmental paradigm

The mammalian adrenal gland is composed of two main components; the catecholaminergic neural crest-derived medulla, found in the center of the gland, and the mesoderm-derived cortex producing steroidogenic hormones. The medulla is composed of neuroendocrine chromaffin cells with oxygen-sensing properties and is dependent on tissue interactions with the overlying cortex, both during development and in adulthood. Other relevant organs include the Zuckerkandl organ containing extra-adrenal chromaffin cells, and carotid oxygen-sensing bodies containing glomus cells. Chromaffin and glomus cells reveal a number of important similarities and are derived from the multipotent nerve-associated descendants of the neural crest, or Schwann cell precursors. Abnormalities in complex developmental processes during differentiation of nerve-associated and other progenitors into chromaffin and oxygen-sensing populations may result in different subtypes of paraganglioma, neuroblastoma and pheochromocytoma. Here, we summarize recent findings explaining the development of chromaffin and oxygen-sensing cells, as well as the potential mechanisms driving neuroendocrine tumor initiation.

Effect of consuming high-fat diet on the morphological parameters of adrenal gland

OBJECTIVES

The incidence of obesity and obesity-assosiated pathologies continues to increase with profound adverse effects on health status in the developed countries.

BACKGROUND

We aimed to investigate the effect of high fat diet on the adrenal gland morphology.

METHODS

We fed the mice with either high-fat diet (60 % kcal from fat) or low-fat diet (10 % kcal from fat) for nine weeks. Unbiased stereological methods were used to evaluate the adrenal gland morphology. The sections were evaluated using Cavalieri's method and volume fraction approach. We calculated mean volume of adrenal gland, mean volume of adrenal medulla, VVadrenal medulla/adrenal gland, mean diameter of cromaffin cells, number of chromaffin cells in per unit volume (NVcc mm‒3), total number of cromaffin cells, VVzona glomerulosa/adrenal cortex, VVzona fasciculata/adrenal cortex , VVzona reticulosa/adrenal cortex.

RESULTS

The weight of adrenal gland, body weight intraperitoneal adipose tissue and adrenal gland weight in the obese mice significantly increased when compared with the control group. No changes were observed in the mean volume of adrenal gland, mean volume of adrenal medulla, VVzona glomerulosa/adrenal cortex, VVzona fasciculata/adrenal cortex, total number of cromaffin cells and diameter of cromaffin cells. However, NVcc mm-3 and VVzona reticulosa/adrenal cortex in the obese mice considerably increased compared with the control group.

CONCLUSION

The present results suggest that high fat diet adversely affects the adrenal gland morphology (Tab. 2, Fig. 6, Ref. 28).

Overexpression of P2X3 and P2X7 Receptors and TRPV1 Channels in Adrenomedullary Chromaffin Cells in a Rat Model of Neuropathic Pain

We have tested the hypothesis that neuropathic pain acting as a stressor drives functional plasticity in the sympathoadrenal system. The relation between neuropathic pain and adrenal medulla function was studied with behavioral, immunohistochemical and electrophysiological techniques in rats subjected to chronic constriction injury of the sciatic nerve. In slices of the adrenal gland from neuropathic animals, we have evidenced increased cholinergic innervation and spontaneous synaptic activity at the splanchnic nerve–chromaffin cell junction. Likewise, adrenomedullary chromaffin cells displayed enlarged acetylcholine-evoked currents with greater sensitivity to α-conotoxin RgIA, a selective blocker of α9 subunit-containing nicotinic acetylcholine receptors, as well as increased exocytosis triggered by voltage-activated Ca²⁺ entry. Altogether, these adaptations are expected to facilitate catecholamine output into the bloodstream. Last, but most intriguing, functional and immunohistochemical data indicate that P2X3 and P2X7 purinergic receptors and transient receptor potential vanilloid-1 (TRPV1) channels are overexpressed in chromaffin cells from neuropathic animals. These latter observations are reminiscent of molecular changes characteristic of peripheral sensitization of nociceptors following the lesion of a peripheral nerve, and suggest that similar phenomena can occur in other tissues, potentially contributing to behavioral manifestations of neuropathic pain.

Selective Pharmacogenetic Activation of Catecholamine Subgroups in the Ventrolateral Medulla Elicits Key Glucoregulatory Responses

Catecholamine (CA) neurons in the ventrolateral medulla (VLM) contribute importantly to glucoregulation during glucose deficit. However, it is not known which CA neurons elicit different glucoregulatory responses or whether selective activation of CA neurons is sufficient to elicit these responses. Therefore, to selectively activate CA subpopulations, we injected male or female Th-Cre+ transgenic rats with the Cre-dependent DREADD construct, AAV2-DIO-hSyn-hM3D(Gq)-mCherry, at one of four rostrocaudal levels of the VLM: rostral C1 (C1r), middle C1 (C1m), the area of A1 and C1 overlap (A1/C1), and A1. Transfection was highly selective for CA neurons at each site. Systemic injection of the Designer Receptor Exclusively Activated by Designer Drugs (DREADD) receptor agonist, clozapine-N-oxide (CNO), stimulated feeding in rats transfected at C1r, C1m, or A1/C1 but not A1. CNO increased corticosterone secretion in rats transfected at C1m or A1/C1 but not A1. In contrast, CNO did not increase blood glucose or induce c-Fos expression in the spinal cord or adrenal medulla after transfection of any single VLM site but required dual transfection of both C1m and C1r, possibly indicating that CA neurons mediating blood glucose responses are more sparsely distributed in C1r and C1m than those mediating feeding and corticosterone secretion. These results show that selective activation of C1 CA neurons is sufficient to increase feeding, blood glucose levels, and corticosterone secretion and suggest that each of these responses is mediated by CA neurons concentrated at different levels of the C1 cell group.

[Pheochromocytoma giant cystic: a case report]

The giant cystic pheochromocytoma is a rare adrenal tumor in the predominantly asymptomatic course; so many cases are not diagnosed until the time of surgery. The simple mobilization of the tumor is associated with the passage to the blood of large amounts of catecholamines and high morbidity and mortality. So the surgery itself and perioperative management are a huge challenge. This article describes the case of a malignant giant pheochromocytoma (35 cm) which occupied the entire right abdomen. Even with the preoperative diagnosis of pheochromocytoma, pharmacological blockade preoperative and intraoperative measures, the patient died shortly before the end of surgery.

Intrastriatal Cografts of Autologous Adrenal Medulla and Sural Nerve in MPTP-Induced Parkinsonian Macaques: Behavioral and Anatomical Assessment

To examine the effects of autologous sural nerve and adrenal medullary tissue intrastriatal cografts upon voluntary motor performance in parkinsonism, a non-human primate 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model was employed to quantitatively assess skilled hand movements. Motor performance was studied in normal, MPTP-induced parkinsonian, and then cografted states. Reaction and movement times were prolonged and variability increased in experimental and control animals in the parkinsonian state. Animals undergoing autologous cografts demonstrated improved motor performance whereas the control animal continued in a chronic, stable parkinsonian state. Intrastriatal cografts of autologous adrenal medullary tissue and sural nerve resulted in good to excellent chromaffin cell survival. The mechanism of the restoration of function in the cografted monkeys remains to be determined.

Immunological Responses to Injury and Grafting in the Central Nervous System of Nonhuman Primates

Allogeneic transplantation for the therapy of human Parkinson's disease is being considered as a viable approach at several clinical centers worldwide. As an attempt to understand the basic biology of central nervous system (CNS) transplantation, our laboratory has developed an experimental nonhuman primate model for human Parkinson's disease and carried out preliminary studies directed at evaluating the potential pathology at the graft site. In addition, studies have been conducted to examine whether such transplantation procedures lead to specific and/or nonspecific immunologic sensitization of the host or results in generalized immunosuppression. Groups of rhesus macaques (Macaca mulatta) were either controls operated (n = 6), autografted with adrenal medullary and peripheral nerve tissue (n = 3), or allografted with fetal mesencephalic tissue (n = 6). Immunohistological studies demonstrated the presence of mononuclear cell infiltrates as early as 1 wk and up to 1 yr postoperatively, although the frequency of the infiltrating cells declined with time. The infiltrates consisted of variable numbers of cells which express CD2+, CD3+, CD4+, CD8+, CD19+, CD22+, CD25+, and CD68+. There appeared to be no difference in the frequency, kinetics, or phenotype of the infiltrating cells in operative controls compared with recipients of auto- or allografts. Tissue sections obtained postoperatively showed low levels of major histocompatibility complex (MHC) Class I antigens and no detectable level of MHC-Class II antigens in neural tissue. A small aliquot of tissue from the operative site was placed in vitro with media containing interleukin-2 (IL-2), which led to the exudation and growth of mononuclear cells that were predominantly CD4+ cells. Phenotypic studies of peripheral blood mononuclear cells (PBMC) from operative controls, auto- and allograft recipient monkeys performed at varying time periods postoperatively failed to show differences in the frequencies of subsets of T-cells, B-cells, NK-cells, or monocytes. Studies on aliquots of the same PBMC failed to show major functional differences in NK-cells, LAK cells, or response to polyclonal mitogens. Finally, recipients of allogeneic mesencephalic grafts failed to show evidence of donor-specific humoral or cellular sensitization. These data indicate that transplantation of autograft adrenal or allograft fetal mesencephalic tissues in the CNS of nonhuman primate did not induce detectable donor-specific sensitization nor nonspecific immunosuppression.

Expression of Extracellular Signal-regulated Kinase 5 and Ankyrin Repeat Domain 1 in Composite Pheochromocytoma and Ganglioneuroblastoma Detected Incidentally in the Adult Adrenal Gland

Composite pheochromocytoma (cPC) is extremely rare, arising in the adrenal medulla as a mixture of PC and other tumors of neural origin. We herein report on a case of adrenal incidentaloma post-operatively diagnosed as cPC with ganglioneuroblastoma (GNBL). The PC component had 7 points on the PASS, a Ki-67 index of 5.1%, a focal absence of sustentacular cells, and no genetic aberrations in succinate dehydrogenase subunit B. The GNBL component exhibited no N-myc amplification. Tumor cells of both components were stained positively for extracellular signal-regulated kinase 5 and ankyrin repeat domain 1. The aberrant activation of growth signaling may play a role in the marginal malignancy of cPC.

Morphology, Biochemistry, and Pathophysiology of MENX-Related Pheochromocytoma Recapitulate the Clinical Features

Pheochromocytomas (PCCs) are tumors arising from neural crest-derived chromaffin cells. There are currently few animal models of PCC that recapitulate the key features of human tumors. Because such models may be useful for investigations of molecular pathomechanisms and development of novel therapeutic interventions, we characterized a spontaneous animal model (multiple endocrine neoplasia [MENX] rats) that develops endogenous PCCs with complete penetrance. Urine was longitudinally collected from wild-type (wt) and MENX-affected (mutant) rats and outputs of catecholamines and their O-methylated metabolites determined by mass spectrometry. Adrenal catecholamine contents, cellular ultrastructure, and expression of phenylethanolamine N-methyltransferase, which converts norepinephrine to epinephrine, were also determined in wt and mutant rats. Blood pressure was longitudinally measured and end-organ pathology assessed. Compared with wt rats, mutant animals showed age-dependent increases in urinary outputs of norepinephrine (P = .0079) and normetanephrine (P = .0014) that correlated in time with development of tumor nodules, increases in blood pressure, and development of hypertension-related end-organ pathology. Development of tumor nodules, which lacked expression of N-methyltransferase, occurred on a background of adrenal medullary morphological and biochemical changes occurring as early as 1 month of age and involving increased adrenal medullary concentrations of dense cored vesicles, tissue contents of both norepinephrine and epinephrine, and urinary outputs of metanephrine, the metabolite of epinephrine. Taken together, MENX-affected rats share several biochemical and pathophysiological features with PCC patients. This model thus provides a suitable platform to study the pathogenesis of PCC for preclinical translational studies aimed at the development of novel therapies for aggressive forms of human tumors.

Diverse proportion in composite pheochromocytoma-ganglioneuroma may induce varied clinical symptom: comparison of two cases

Composite pheochromocytoma-ganglioneuroma is extremely rare. We described two cases of composite pheochromocytomas in the adrenal medullar. Case 1 was a 70-year-old male presenting with lower abdominal pain and normal blood electrolytes. Case 2 was a 48-year-old female with palpitation and back tenderness. Biochemical investigations showed hypocalcium, hypokalemia and high level of vma. The histological images and the immunohistochemical staining demonstrated the two cases composed of pheochromocytoma and ganglioneuromoma components. Ganglioneuroma component in case 2 accounted for more proportion than that in case 1. We speculated that the varied clinical symptoms were related with the diverse proportions in composite pheochromocytome-ganglioneuroma.

Studies of neurotransmitter release in the pathogenesis of hypertension

Studies using a sensitive radioenzymatic assay for plasma noradrenaline suggest there is a selective overactivity of the sympathetic nervous system in essential hypertension. Methodology which allows the study of local sympathetic turnover in CNS nuclei and peripheral blood vessels is described. This approach has been used to study the non-innervated sympathetic turnover phaeochromocytoma. It is suggested that studies of local regulatory mechanism in neurotransmitter release are required to give a greater understanding of the central and peripheral role of the sympathetic nervous system in the pathogenesis of hypertension.

A rarely seen case among retroperitoneal mass lesions: paraganglioma

Pheochromocytomas are rarely seen cathecolamine-secreting neuroendocrine tumors. Diagnosis, treatment, and prognosis of this rarely seen condition have been discussed. In this study, a retroperitoneal paraganglioma with a diameter of 27 mm was detected in a 29-years old nephrectomized male patient. In our case, in reevaluations performed after definitive establishment of the diagnosis, any abnormal radiological signs suggesting a metastatic lesion were not detected. During the postoperative period the patient was referred to the clinics of endocrinology, and oncology for medical follow-up. In the differential diagnosis of retroperitoneal mass lesions, pheochromocytoma/paraganglioma should not be forgotten. Besides, for malignant tumors chemoradiotherapy, and for benign functional tumors medical treatment should be applied.

[Diagnosis and treatment of adrenal medullary hyperplasia]

OBJECTIVE

To explore the clinical characters of adrenal medullary hyperplasia (AMH).

METHODS

The clinical data of 7 cases of AMH admitted from 1996 to 2013 were analyzed with a review of literature.

RESULTS

There were 3 males and 4 females with a median age of 36 (23-69) years. All had hypertension at first diagnosis and 2 were paroxysmal. Computed tomography (CT) scan revealed unilateral adrenal nodule in all cases, including left (n = 5) and right (n = 2) side. The diameter of nodules was 0.9 cm to 3.0 cm.Hypokalemia was found in 2 cases. And 24-hour output of urine catecholamine was higher than normal level in 2 cases. An abnormal rise of 24-hour output of urine free cortisol was found in 1 case with a lower level of adrenocorticotropic hormone (ACTH) simultaneously while a lower level of plasma renin activity in vertical position was found in another case. Three patients received (131)I-meta-iodobenzylguanidine scan and one had positive result. Pre-operative diagnosis included pheochromocytoma (n = 2), adrenocortical adenoma (n = 3) (2 aldosterone-producing adenomas, 1 Cushing adenoma) and undetermined adrenal tumor (n = 2). All underwent surgery, including unilateral adrenalectomy (n = 4) and resection of adrenal disease (n = 3). All cases had a pathologic diagnosis of AMH. One had concurrent Cushing adenoma while another with cortical hyperplasia.One case achieved normotension postoperatively while others showed varying decreases of blood pressure, but remained hypertensive.

CONCLUSION

With a common feature of hypertension, AMH is difficult to diagnose preoperatively. CT scan has a certain diagnostic significance and a definite diagnosis depends on pathological examination; because of inaccurate preoperative and intraoperative diagnosis, the extent of surgery may be incomplete and results in unsatisfied outcomes.

The adrenal medulla and extra-adrenal paraganglia: then and now

The past 25 years have witnessed revolutionary changes in the care of patients with pheochromocytomas and extra-adrenal paragangliomas. Germline mutations of at least 13 genes are now associated with tumor development, a greater degree of hereditary susceptibility than for any other human neoplasm. Somatic mutations, either of the same genes or of several additional ones with closely related functions, are also increasingly recognized. Clinicians are now aware of the genetic implications of a pheochromocytoma or paraganglioma. All patients are therefore offered genetic testing and receive lifelong surveillance. Almost all of the mutated genes have well-described correlations with clinical and biochemical phenotypes. Tumors arising in patients with mutations of the SDHB gene have at least a 30 % chance of metastasizing and typically produce norepinephrine and/or dopamine. Assay of plasma-free metanephrines serves as a highly sensitive and specific biochemical screen for the presence of catecholamine-producing tumors, and the dopamine metabolite methoxytyramine serves as a useful marker for detecting minimally functional tumors or their metastases. New functional imaging techniques provide highly sensitive tumor localization. In addition to differential diagnosis, pathologists play new roles in helping to identify hereditary disease and guiding the sequence of genetic testing.

Investigating the role of adrenal cortex in organization and differentiation of the adrenal medulla in mice

Functions of adrenal medulla, particularly synthesis of catecholamine, are under the control of glucocorticoids produced by the cortex. To further investigate whether development/differentiation of the adrenal medulla is associated with proper organization of the adrenal cortex, we examined development of the medulla in four different mouse models with various defects in the adrenal cortex. By using the Sf1/Cre mouse line that inactivates/activates genes in Steroidogenic factor 1 (SF1)-positive cells of the fetal adrenal cortex, we produced mice that exhibit either (1) cortex hypoplasia, (2) progressive degeneration of fetal adrenal cortex, (3) cortex dysgenesis, or (4) cortex-medulla disorganization. The formation of phenylethanolamine N-methyltransferase (PNMT)-positive medulla in all models indicates that differentiation of adrenal medulla is independent of the growth of adrenal cortex. However, the misplaced/dysgenic medulla in embryos where β-catenin expression is altered, suggests that the β-catenin pathway in the adrenal cortical cells plays an indirect role in controlling proper organization of the adrenal medulla.

[Pheochromocytomas in adrenal medulla or extra-adrenal and multiple endocrine neoplasms:a clinicopathologic analysis of 181 cases]

OBJECTIVE

To analyze the change in the incidence of pheochromocytomas in adrenal medulla or extra-adrenal and multiple endocrine neoplasm type 2 (MEN2), to summarize the clinical characteristics of benign, potentially malignant and malignant pheochromocytomas and to investigate the correlation between clinical manifestations and pathological changes.

METHODS

Statistic analysis was performed to detect the incidence, constituent ratio, mean diagnostic age, sex proportion and correlation between clinical manifestions and pathologic changes in pheochromocytomas in adrenal medulla or extra-adrenal gland and MEN2 from 1993 to 2008 in the Department of Pathology, the General Hospital of Tianjin Medical University with Runs test, ANOVA, t test and chi-square test.

RESULTS

The total number of biopsies within the 16 years was 167 702 cases (average 10 481 cases per year). The numbers (detectable rate) of total adrenal diseases, pheochromocytomas in adrenal medulla and extra-adrenal glands were 910 (0.54%), 139 (0.08%), and 42 (0.03%) cases, respectively. The numbers (constituent ratio) of benign, potentially malignant and malignant of pheochromocytomas in adrenal medulla were 102 cases (73.4%), 29 cases (20.9%) and 8 cases (5.7%), respectively; in the 102 cases of benign tumors, patients with MEN2 were 8 (7.8%); the three groups of the tumors in extra-adrenal sites were 18 (42.8%) cases, 12 (28.6%) cases and 12 (28.6%) cases. There were no changes in the detectable rate and constituent ratio of adrenal diseases, benign, potential malignant and malignant pheochromocytomas in adrenal medulla or extra-adrenal glands and patients with MEN2 during the past 16 years (P > 0.05), but there was a tendency that malignant transformation was gradually increased with age, which was more commonly found in male patients than females. The mean age at diagnosis of patients with benign and potentially malignant pheochromocytomas was 42.7 years (ranged from 10 - 74 years), and 40.1 years (13 - 66 years), respectively, which were younger than patients with malignant pheochromocytomas (51.6 years, P < 0.05); the mean age of patients with benign and potentially malignant pheochromocytomas in extra-adrenal sites was 43.1 years (ranged from 20 - 75 years) and 45.2 years (28 - 65 years) that were older than those with malignant (37.8 years, ranged from 14 - 58 years, P < 0.05). It was spectacular that patients with malignant pheochromocytoma in adrenal medulla (51.6 years) were older than that in extra-adrenal sites (37.8 years); all the patients with MEN2 were female benign pheochromocytoma in adrenal medulla, whose age (38.9 years) was younger than that of benign lesions (42.7 years, P < 0.05), in which thyroid medullary carcinoma appeared early than pheochromocytomas in adrenal medulla. The detectable rate of hypertension in patients with malignant pheochromocytomas in adrenal medulla and in extra-adrenal sites were less than that in benign and potentially malignant ones (P < 0.05). The bilateral lesions more commonly found in malignant pheochromocytoma (25.0%) than benign (15.7%) and potentially malignant pheochromocytomas (6.9%) only in adrenal medulla. Relapse rates in both adrenal and extra-adrenal tumors were rising from benign (11.8%, 0), potentially malignant (13.8%, 25.0%), to malignant (33.3%, 37.5%) groups; the average diameter of pheochromocytomas in both adrenal and extra-adrenal sites was increasing from benign (4.2 cm, 4.0 cm), potentially malignant (5.3 cm, 5.6 cm) to malignant (7.3 cm, 6.9 cm) groups (P < 0.05).

CONCLUSIONS

The diagnostic criteria of benign, potentially malignant and malignant pheochromocytomas in adrenal medulla and in extra-adrenal sites are well established according to the WHO classification of endocrine tumors (2004). The closer relationship is found between clinical manifestations and pathologic changes. The definite type and nature of pheochromocytomas are mainly rested upon the pathologic examination.