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.

Juxtaglomerular cell tumor: report of a case with unusual presentation

ABSTRACT Juxtaglomerular cell tumor is a benign, renin-secreting neoplasm. The tumor arises from the juxtaglomerular apparatus cells of the kidney. Because the tumor is hormonally active, patients usually suffer from hypokalemia, hyperaldosteronism, and hypertension. Herein, we describe a case of a 19-year-old Asian female with a somewhat unusual presentation. A 19-year-old Asian female presented with upper extremity weakness, numbness, and tingling. On physical examination, the only notable finding was hypertension. Extensive workup revealed elevated aldosterone level and plasma renin activity. CT scan of the abdomen revealed a 2.2 cm mass in the lower pole of the left kidney. The mass was resected by partial nephrectomy. On microscopic evaluation, the tumor had glomoid appearance with sheets of uniform, round to polygonal cells with clear to eosinophilic cytoplasm. Immunohistochemical stains showed the tumor cells to be positive for CD117, CD34 and CD10 and negative for ER, PR, CK7, PAX-8, pan-cytokeratin, EMA, S100, Melan-A, HMB45, SMA and CAIX. Diagnosis of Juxtaglomerular cell tumor was rendered. This case highlights the importance of a regular physical exam and a high index of suspicion in patients presenting with unusual complaints.

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.

The significance of the amoebocyte-producing organ in Biomphalaria glabrata

In molluscs, internal defence against microorganisms is performed by a single cell type, i.e., the haemocyte or amoebocyte. The origin of these cells in Biomphalaria glabrata was initially thought to be localised within the vasculo-connective tissue. More recently, origin from a single organ, termed the amoebocyte-producing organ (APO), has been postulated based on the occurrence of hyperplasia and mitoses during Schistosoma mansoni infection. The present investigation represents a histological, immuno-histochemical and ultra-structural study of the B. glabrata APO, whereby histological identification was facilitated by means of collecting epithelial basophilic cells. These cells were comprised of single-cell layers that cover a portion of the stroma, which contains many small, round cells and haemolymph sinuses, as well as a small area of the pericardial surface of the reno-pericardial region. On occasion, this epithelial component vaguely resembled the vertebrate juxtaglomerular apparatus, which reinforces its presumed relationship to the kidney. Both in normal and infected molluscs, mitoses were only occasionally found. The present quantitative studies failed to demonstrate the presence of APO cellular hyperplasia, either in normal or schistosome-infected B. glabrata. Conversely, several structural details from the APO region in B. glabrata were found to be consistent with the hypothesis that the APO is a filtration organ, i.e., it is more closely related to the kidney rather than the bone marrow, as has been suggested in the literature.

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.

Mechanism of angiotensin Ⅱ in regulation of renin synthesis in juxtaglomerular granular cells / 中华肾脏病杂志

Objective To elucidate the mechanism of angiotensin (Ang) Ⅱ in regulation of renin synthesis and secretion in primary cultured juxtaglomerular granular cells (JGCs). Methods Mice JGCs were isolated and cultured as described before. Real-time PCR was used to demonstrate the expression of angiotensin converting enzyme (CE) and angiotencin receptor (AT1, AT2) in JGCs. Ang Ⅱ was co-cultured with JGCs stimulated by PGE2 and isoproternol or not. Renin activity in supernatant was detected by radioimmunoassay and renin mRNA expression was examined by real-time PCR. Different concentrations of Ang Ⅱ were co-cultured with JGCs with different time (1 h, 4 h and 24 h), cAMP in cell lysate and supernatant was measured by Cayman Cyclic AMP EIA Kit. The cytoplasmic calcium was decreased by BAPTA-AM, and increased by thapsigargin and cyclopiazonic acid, which could be used to observe the cAMP concentration affected by calcium. Adenylyl cyclase type 5, 6 (AC5, AC6) mRNA expression of JGCs co-cultured with Ang Ⅱ was measured by real-time PCR. Results Real-time PCR confirmed the expression of ACE and AT mRNA in JGCs of WT mice. Angiotensin Ⅱ reduced renin secretion in primary cultures of JGCs [(370.6±36.9) vs (299.6±25.7) ng AngI'ml~(-1)·h~(-1), P=0.014]. Angiotensin Ⅱ dose-dependently down-regulated forskolin-stimulated cAMP production in JGCs. Thapsigargin and cyclopiazonic acid decreased cAMP level. BAPTA-AM increased cAMP production obviously [(11.09±0.48) vs (3.55±0.47) nmol/L, P<0.01]. Ang Ⅱ inhibited AC5 mRNA expression by 42.12%, but did not inhibit AC6 mRNA expression. Conclusions Angiotensin Ⅱ can directly inhibit renin synthesis and secrestion maybe through reducing AC-stimulated cAMP levels. Crosstalk between calcium and cAMP system may exist in precise regulation of renin in JGCs.

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.

OBSERVATION OF THE RENAL GLOMERULUS CASTS OF DOG UNDER THE SCANNING ELECTRON MICROSCOPE / 解剖学报

The kidneys removed from six female adult dogs were injected through the renal artery with ABS at a constant pressure between 33.3—33.7 kPa(250—280mmHg). Small specimens cut out from the kindneys were digested in 3％ trypsin solution for 48 hours and then eroded in 50％ HCl. The cast specimens were studied under the scanning electron microscope. The results were outlined as follows: 1. The corrosion-cast models of the renal glomerulus of the dogs observed under the SEM could be divided into three kinds: the spherical glomerulus, the chrysanthemum-like glomerulus and mixed glomerulus. 2. In general, the afferent and efferent arteriolae entered or exited at the hilum of glomerulus. Rarely, the efferent vessel left the glomerulus at the opposite side of the hilum. Anastomoses between the afferent and efferent or between the efferents vessels were found in our casts. 3. The capillary network of the juxtaglomerular apparatus was observed at the hilum of glomerulus in our casts. The diameters of the meshes of the capillary network were smaller than that of the vessels themselves.