Tumor de células yuxtaglomerulares (reninoma) como causa de hipertensión arterial en la adolescencia. A propósito de un caso / Juxtaglomerular cell tumor (reninoma) as a cause of arterial hypertension in adolescents. A case report

La hipertensión arterial (HTA) grave en pediatría responde fundamentalmente a causas secundarias. Presentamos una paciente adolescente de 14 años con HTA grave, alcalosis metabólica e hipopotasemia, secundaria a un tumor de células yuxtaglomerulares productor de renina, diagnosticado luego de dos años de evolución de HTA.

Severe arterial hypertension (HTN) in pediatrics is mainly due to secondary causes. Here we describe the case of a 14-year-old female adolescent with severe HTN, metabolic alkalosis, and hypokalemia, secondary to a renin-secreting juxtaglomerular cell tumor diagnosed after 2 years of HTN progression.

Reninoma: a rare cause of curable hypertension / 소아과

The most common type of refractory hypertension found in children is secondary hypertension, which is a potentially curable disease. Reninoma, a renin-secreting juxtaglomerular cell tumor, is a rare cause of severe hypertension that is usually diagnosed in adolescents and young adults. Surgical resection of the tumor completely cures the hypertension of patients with reninoma. The typical clinical presentation of reninoma includes hypokalemia, metabolic alkalosis, and features secondary to the increased activation of the renin-angiotensin system without renal artery stenosis. We report a case of reninoma in a female adolescent with a typical clinical presentation, in which surgical removal of the tumor completely cured hypertension. We discuss here the clinical features, imaging studies, and immunohistochemical examination of the tumor used to establish the diagnosis of reninoma and for the management of the condition.

Nephron-sparing surgery for treatment of reninoma: a rare renin secreting tumor causing secondary hypertension

Main findings A 25-year-old hypertensive female patient was referred to our institution. Initial workup exams demonstrated a 2.8 cm cortical lower pole tumor in the right kidney. She underwent laparoscopic partial nephrectomy without complications. Histopathologic examination revealed a rare juxtaglomerular cell tumor known as reninoma. After surgery, she recovered uneventfully and all medications were withdrawn. Case hypothesis Secondary arterial hypertension is a matter of great interest to urologists and nephrologists. Renovascular hypertension, primary hyperadosteronism and pheocromocytoma are potential diagnosis that must not be forgotten and should be excluded. Although rare, chronic pyelonephritis and renal tumors as rennin-producing tumors, nephroblastoma, hypernephroma, and renal cell carcinoma might also induce hypertension and should be in the diagnostic list of clinicians. Promising future implications Approximately 5% of patients with high blood pressure have specific causes and medical investigation may usually identify such patients. Furthermore, these patients can be successfully treated and cured, most times by minimally invasive techniques. This interesting case might expand knowledge of physicians and aid better diagnostic care in future medical practice. .

Electron microscopic evaluation of the secretory mechanisms of renin from juxtaglomerular cells / Evaluación con microscopía electrónica de los mecanismos secretorios de renina desde las células juxtaglomerulares

Although the structure and the functions of juxtaglomerular cells (JG) have been well defined, there is still a controversy about the secretory mechanisms of renin from these cells. It has been assumed that exocytosis is the main secretory mechanism in these cells in many studies, while others suggest that secretion occurs in a quite different way in these cells. There are several studies suggesting that diacrine secretion, which is very difficult to visualize, might be the other mechanism for secretion of renin. This study is an attempt to find the answers of these questions by identifying the fine structural features of the secretory granules in juxtaglomerular cells. Cyclosporin A (CyA) has been used in the current experimental study since it has already been reported that this drug increases the number of JG cells and stimulates secretion of Renin. Twelve female Sprague-Dawley rats had daily intraperitoneal injections of CyA for ten weeks. Tissue specimens from the kidneys of these animals were examined by electron microscopy. Fine structural characteristics of the secretory granules of juxtaglomerular cells have been examined. Considerable amount of granules, which goes to the exocytotic process, have been observed. Additionally, several cells, which their granules had been secreting their contents in a different way, were found. This was interpreted as the secretion type of diacrine secretion. In conclusion, this in vivo study presents morphologic evidences demonstrating that both exocytosis and diacrine secretion might occur in JG cells. We also had a chance to observe secretory granule probably exhibiting "diacrine secretion", which is very difficult to visualize, at electron microscope level for the first time. This report also provides morphologic proof which shows that these two distinct secretory mechanisms might occur simultaneously in the same juxtaglomerular cell.

Aunque la estructura y las funciones de las células yuxtaglomerulares (JG) han sido bien definidas, todavía existe controversia acerca de los mecanismos de secreción de renina en estas células. Se ha supuesto, en muchos estudios, que la exocitosis es el principal mecanismo de secreción de estas células, mientras que otros autores sugieren que la secreción se produce de una manera muy diferente en estas células. Hay varios estudios que plantean que la secreción diacrina, que es muy difícil de visualizar, podría ser otro mecanismo para la secreción de renina. Este estudio tiene como objetivo encontrar las respuestas a estas interrogantes mediante la identificación de las características estructurales de la secreción de gránulos en las células yuxtaglomerulares. Ciclosporina A (CyA) se ha utilizado en el estudio experimental actual, debido a que se ha informado que este medicamento aumenta el número de células JG y estimula la secreción de renina. Doce ratas hembras Sprague-Dawley fueron diariamente inyectadas por vía intraperitoneal, con CyA durante diez semanas. Las muestras de tejido renal de estos animales fueron examinadas a través de microscopía electrónica. Detalladas características estructurales han sido examinadas en los gránulos secretores de las células yuxtaglomerulares. Se ha observado una cantidad considerable de gránulos, que va con el proceso de exocitosis. Además, se encontaron células que habían secretado el contenido de sus gránulos de manera diferente. Esto fue interpretado como secreción de tipo diacrina. En conclusión, este estudio in vivo presenta evidencias morfológicas que demuestran que tanto la exocitosis y la secreción diacrina podría ocurrir en células JG. También tuvimos la oportunidad de observar probables gránulos secretores, que mostrarían "la secreción diacrina", que es muy difícil de visualizar, a nivel de microscopía electrónica. Este informe también proporciona la prueba morfológica que demuestra que estos dos mecanismos...

A Case of Juxtaglomerular Cell Tumor Combined with Focal Segmental Glomerulosclerosis / 대한신장학회지

Juxtaglomerular cell tumor is a rare cause of secondary hypertension. Focal segmental glomerulosclerosis (FSGS) is a clinicopathological entity associated with renal insufficiency and proteinuria. The exact diagnosis and proper management are important in both juxtaglomerular cell tumor and FSGS. We experienced a 26-year-old male who complained of a palpable abdomen mass associated with proteinuria and hypertension. Ultimately, he was diagnosed with a juxtaglomerular cell tumor combined with FSGS after nephrectomy. After operation, his hypertension normalized, while his renal function deteriorated.

Uncoupling protein-2 expression in granular cells and embryo development in in vitro fertilization-embryo transfer cycle / 南方医科大学学报

<p><b>OBJECTIVE</b>To examine the expression of uncoupling protein-2 (UCP2) in the granular cell of women undergoing in vitro fertilization (IVF) and explore its role in embryo development.</p><p><b>METHODS</b>In this prospective study, the levels of UCP2 and reactive oxygen species (ROS) were measured by the chemiluminescence method in the granular cell of 53 women.</p><p><b>RESULTS</b>Women with low UCP2 level had higher ROS level, suggesting an inverse relationship between them (r=-0.578, P<0.01), and their oocyte development was impaired. Granular cells of elder women exhibited lowered UCP2 expression.</p><p><b>CONCLUSION</b>The granular cells increase UCP2 expression to suppress the elevation of intracellular ROS level through a feedback mechanism and therefore protect the oocytes against oxidative stress.</p>

Clinicopathological study of 4 renal juxtaglomerular cell tumors / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the clinical characteristics, morphologic and immunohistochemical features, diagnosis, differential diagnosis, histogenesis and prognosis of renal juxtaglomerular cell tumor (JGCT).</p><p><b>METHODS</b>Light microscopic observation; immunohistochemical assay of CK8, E-cadherin/CK7, CD10, Vim, Actin, CD34, S100, HMB45, CD31, Chr, Syn and CD117, EM; and follow-up were done on all 4 surgically treated JGCT patients.</p><p><b>RESULTS</b>All 4 JGCT were observed in young adult with clinically uncontrolled severe hypertension. Grossly, the tumor was encapsulated and small in size. Microscopically, the tumor cells grew in sheets predominantly, but papillary and onion-like pattern could also be seen. The stroma contained prominent vasculature that consisted of numerous thin-wall vessels clustering around thick-walled vessels. Tumor cells were rather small, polygonal, with slightly eosinophilic cytoplasm and ill-defined cell border. Nuclei were uniform in size but nuclear atypia and mitosis could be seen. Numerous mast cells were scattered among the tumor cells, and tubules were identified in 3 of 4 cases with positive expression of distal tubule marker of E-cadherin/CK7. Tumor cells positively expressed Vim, Actin, calponin, and CD34. All cases presented ultrastructural features of distinct rhomboid-shaped crystal. There was no recurrence or metastasis but hypertension persisted in three during follow-up (mean 37 months) for all 4 JGCT patients.</p><p><b>CONCLUSION</b>JGCT, originating from the juxtaglomerular cell, has a distinct benign entity, and it is typically found in young adults with severe hypertension. It has a unique morphology and ultrastructure features and positive immunoreactivity to Vim, Actin, calponin and CD34.</p>

Juxtaglomerular cell tumor as a rare cause of hypertension in adults

The juxtaglomerular cell tumor is a cause of secondary hypertension in adults. A 35-year-old female patient suffering from hypertension and low serum potassium had a 3 x 3 cm solid mass at the lower pole of left kidney diagnosed by abdominal sonography. Partial nephrectomy was performed and the postoperatory was uneventful. Normalization of blood pressure was observed within the first month.

Juxtaglomerular cell tumor of the kidney: a clinicopathologic analysis of five cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the morphologic characteristics and immunophenotype of juxtaglomerular cell tumor of the kidney (JGCT), with discussion on its diagnostic clues and possible histogenesis.</p><p><b>METHODS</b>The clinical, pathologic and immunohistochemical features of 5 cases of JGCT were evaluated. In addition, 5 cases of hemangiopericytoma and 5 cases of cutaneous glomus tumor were selected for comparative immunohistochemical analysis.</p><p><b>RESULTS</b>The JGCT cases came from 4 females and 1 male (mean age at diagnosis = 32 years). All of them manifested symptoms of systemic hypertension. Four of the patients received partial nephrectomy and the remaining patient was treated by radial nephrectomy. All of them were followed up for a period of 4 to 66 months (average = 27 months). There was no evidence of local recurrence or distant metastases. On gross examination, these JGCTs were well-circumscribed and situated in the renal cortex and measured 4.4 cm in greatest dimension on average. Histologically, the tumor was characterized by the following three features: (1) solid sheets of relatively uniform polygonal to round cells with lightly eosinophilic cytoplasm, sometimes containing PAS-positive intracytoplasmic granules; (2) absence of or very scanty mitotic figures; (3) interstitium rich in thin-walled capillaries, associated with focal hyaline change and hemangiopericytoma-like architectural pattern. Under electron microscopy, characteristic rhomboid-shaped renin granules were found in the cytoplasm. All JGCTs were immunoreactive for renin, CD34, actin, and calponin. In contrast, all glomus tumors were negative for renin and all hemangiopericytomas were negative for actin.</p><p><b>CONCLUSIONS</b>JGCT is a rare benign renal neoplasm typically found in young adults and manifests as systemic hypertension. The tumor cells may be originated from modified vascular smooth muscle cells. The identification of renin granules by electron microscopy and demonstration of the characteristic immunophenotype is the key to correct pathologic diagnosis.</p>

A Case of Bartter Syndrome with Muscle Weakness and Short Stature

Bartter syndrome is a rare disorder characterized by the association of hypokalemic hypochloremic metabolic alkalosis, hyperreninemia, hyperaldosteronemia, short stature and nephrocalcinosis. This disorder presents with hyperplasia of juxtaglomerular apparatus on renal biopsy. We experienced a case of late-onset Bartter syndrome with nephrocalcinosis in a 9-year-old boy, whose chief pictures were muscle weakness, short stature, persistent sterile pyuria and microscopic hematuria. We report this case with a brief review of related literatures.

A Case of Severe Hypokalemia Induced by Chronic Furosemide Abuse / 대한신장학회잡지

A 46-year-old woman was admitted to emergency room for muscle weakness and repiratory difficulty. She was taking furosemide (4 tablets per day : 160 mg/day) without physician's prescription. Her blood pressure was 90/50 mmHg and her heart rate 74/ min. Her laboratory finding showed a low serum potassium concentration (0.9 mmol/L), CK 368 IU/L, creatine 1.6 mg/dL. The result was rechecked and confirmed. Electrocardiography showed a dip in the ST segment, prolonged QTc, 1st degree AV block and 2 : 1 AV block. Echocardiography was normal. Abdominal CT scan show right lower pole calyceal stones without nephrocalcinosis. Treatment was initiated consisting of intravenous potassium chloride. Hypokalemia was overcome in 3 days. Kidney biopsy showed hypokalemic nephropathy - interstitial nephrosis, vacuolar change of tubule, proliferation of juxtaglomerular apparatus. Paralytic ileus, rebound pleural effusion, glucose intolerance, elevation of CK were associated findings. After correction of hypokalemia, her symptoms and electrocardiographic findings returned to normal.

Juxtaglomerular cell tumor of the kidney: a case report

We report a case of renin-secreting juxtaglomerular cell tumor which developed in a hypertensive 47-yr-old Korean man. Presumptive clinical diagnosis was made before surgery based on the high level of plasma renin and the radiologic evidence of renal mass. Grossly, a round, bulging, well-encapsulated mass of 3x3 cm was located in the mid-portion of the right kidney. On microscopic examination, the tumor was composed of ovoid to polyhedral cells with bland nuclei, indistinct nucleoli and light eosinophilic cytoplasm. The immunostaining for renin showed strong positivity in the cytoplasm of tumor cells. The characteristic rhomboid shaped renin protogranules were observed in ultrastructural analysis.

Distribution of the Dopamine D1 and D2 Receptor Protein Using Immunohistochemistry in Wistar-Kyoto Rat (WKY) and Spontaneously Hypertensive Rat (SHR) Kidneys / 대한신장학회잡지

The kidney and balances of fluid and volume are the basic components of bloocl pressure control, and the kidney is the primary site that initiates the hypertensive process and is affected by hypertensive vascular disease. In the kidney, the dopamine is a potent natriuretic and vasodilating agent, participat- ing in renal sodium excretion and maintenance of cardiovascular homeostasis. And the dopamine receptors in central nervous system and peripheral organs were identified by physiological, biochernical and radioligand binding techniques. Rut previous morphological and biochemical studies have been unable to characterize or determine the tissue distribution of the dopamine receptor subtypes because no selective ligands are available yet. Furthermore, the cellular distribution of the dopamine receptor subtypes in the rat kidney is not demonstrated well. In the SHR, the ability of exogenous and endogenous renal dopamine to engender a natriuresis is impaired. Since renal dopamine levels in genetic models of hypertension are not lower than their normotensive controls, the impaired intrarenal paracrine effect of dopamine in these animal models of hypertension appears to be receptor or postreceptor mediated. And renal dopamine derives mainly from renal tubular dopamine production and to a lesser extent from dopaminergic nerves. The present study utilizes imrnunohistochemistry with specific antibodies to characterize the renal distribution of dopamine receptor subtypes and recognize the role of dopamine receptor defect in the pathogenesis of hypertension in 14-week-old WKY (mean HP 108+/-5mmHg) and SHR (mean RP 174+/-7 mmHg) kidneys. Also it utilizes antibody of tyrosine hyclroxylase (TH) to recognize the site of the dopamine production mediated by TH using light microscopic immunohistochemistry. In the immunohistochemistry of the WKY kidney, dopamine D1 receptor protein is localized to glomerulus, proximal tubule, distal tubule, renal vessels, cortical and medullary collecting duct. And in the SHR kidney, dopamine D1 receptor protein is localized to glomerulus, distal tubule, renal vessels, cortical and medullary collecting duct, and juxtaglomerular apparatus (JGA). But there is no demonstrable positive reaction in the proximal tubule and weakly positive reactions in the renal arterioles of SHR compared with WKY kidney. In the immunohisto-chemistry of the WKY kidney, dopamine D1 receptor protein is localized to glomerulus, proxirnal tubule, distal tubule, renal vessels, cortical and rnedullary collecting duct. And in the SHR kidney, dopamine D2 receptor protein is localized to glomerulus, distal tubule, renal vessels, cortical and medullary collecting duct, and JGA. So, there is no demonstrable positive reaction in the proximal tubule of SHR compared with WKY. In the glomerulus of the WKY and SHR kidneys, both dopamine D1 and D2 receptors are localized. In the in situ hybridization of the WKY and SHR kidneys, dopamine D and D receptors are only demonstrated at the renal vessels. The positive reaction to TH immunohistochemistry of the WKY and SHR kidneys is only observed in the renal medulla compared with negative reaction on the renal cortex. Considering the excretion of sodium up to 65-70% with volume expansion may be mediated by dopamine D1-like receptors in the proximal tubule, our immunohistochemistry findings for the dopamine receptors may support the failure of natriuretic response in the SHR due to an abnormal dopamine receptor. Also our results rnay mean that the glornerular filtration rate is mediated by both dopamine D1 and Dz receptors comparing with the previous studies that the glomerular filtration rate was mediated by dopamine D2 receptor. I'here are some differences in the receptors expressing sites on the previous radioligand binding and pharmacologic studies, but our results suggest that at least some of the renal dopamine DA and DAz receptors correspond structurally to the central dopamine D1 and D2 receptors. Finally the result of TH immunohisto-chemistry suggests that the production of dopamine in the proximal tubule is not mediated by TH.

Mecanismos de daño renal en la hipertensión arterial / Mechanisms of renal damage in the hipertension

El riñón es un órgano orientado a preservar la homeostasis del medio interno a través de mantener el balance de sodio y agua. La función del aparato yuxtaglomerular es mantener el balance glomérulo-tubular y, por consiguiente, la regulación fina de la excresión de sodio. Existe una población de hipertensos que no pueden suprimir la producción de mRNA angiotensinógeno en respuesta a una carga de sodio y por lo tanto son incapaces de mantener un balance adecuado de este ion, siendo esta una posible causa congénita de hipertensión arterial. La elevación de la presión arterial sistémica se acompaña de cambios en el riñón, como: hipertensión capilar glomerular, aumento de la presión de flujo laminar y disfunción endotelial. Como consecuencia del aumento de la permeabilidad capilar hay pasaje de macromoléculas proteicas y lipídicas al mesangio y al túbulo renal, y la AII actuando sobre las células mesangiales estimula la producción local de factor de crecimiento derivado de las plaquetas y factor de crecimiento tisular b deribado de fibroblastos induciendo un proceso cicatricial progresivo con depósito exagerado de colágeno; tanto en el mesangio glomerular, como en el intersticio glomerular, que conducen a la fase final del daño glomerular que es la esclerosis total con pérdida de la arquitectura renal y reemplazo del tejido funcionante por fibrosis. Los inhibidores ECA, antagonistas de la AII, y algunos bloqueadores de calcio, al normalizar la dinámica glomerular y la presión arterial sistémica ejercen un efecto nefroprotector que los convierte en las drogas de elección para el manejo de la hipertensión arterial.

A Case of Hypokalemic Myopathy Associated with Bartter's Syndrome

Bartter's syndrome is characterized by hyperreninemia, hyperaldosteronism, hypokalemic hypochlorenlic alkalosis, normal blood pressure, juxtaglomerular apparatus hyperplasia, general weakness, and muscle weakness. We experienced a case of hypokalemic myopathy associated with Bartter's syndrome in 15 years old male. He had experienced paroxysmal muscle weakness without sensory change and myalgia since 10 years old. Subsequently, he had complaints of progressive muscle weakness, especially proximal muscles. Prominent juxtaglomerular apparatus with cellular proliferation biopsy was seen in the kidney. And there were mild perivascular inflammatory cell infiltration, small degenerating and/or regenerating muscles fibers, and normal muscle fiber distribution without evidence of chronic myopathy in the muscle biopsy. The patient was sucessfully managed with indomethacin and oral potassium chloride.

A Case of Bartter's Syndrome with a Seizure Disorder Associated with Subdural Hematoma / 영남의대학술지

Bartter's syndrome is a rare tubular disorder characterized by hypokalemic, hypochloremic metabolic alkalosis, hyperreninemic, hyperaldosteronism, hyporesponsiveness to pressor agents and juxtaglomerular apparatus heperplasia. We report a case of Bartter's syndrome of a 5 month-old male infant with subdural hematoma who was confirmed by characteristic clinical, laboratory findings and kidney biopsy.

A case of Bartter's syndrome

Bartter's syndrome is a rare tubular disorder characterized by hypokalemic, hypochloremic metabolic alkalosis, hyperreninemic hyperaldosteronism, hyporesponsiveness to pressor agents, and juxtaglomerular apparatus hyperplasia. We report here a case of Bartter's syndrome in a 5 month-old male infant who improved with potassium supplements. In addition to a case report, brief review of related literatures was done.