initial workup exams demonstrated a 2.8 cm cortical lower pole tumor in the right kidney .
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 .
  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 .
approximately 5% of patients with hypertension have specific secondary causes , which may be identified after meticulous medical history , physical examination , laboratory tests , and image workup .
secondary hypertension might be caused by several conditions affecting the kidneys , heart , arteries , or the endocrine system .
proper treatment addresses the underlying condition and tends to normalize blood pressure , reducing the risk of severe heart , kidney and brain complications .
the purpose of this article is to report and illustrate an interesting case where radiological investigation discovered a renal tumor as a possible cause of hypertension .
a 25-year - old female patient was referred for examination at our institution because of severe hypertension .
when she arrived to our office , she was already taking propanolol , hydrochlorotyazide and spironolactone for blood pressure control .
physical examination was essentially normal except for persistent high blood pressure ( systemic blood pressure = 150x100 mmhg ) .
laboratory screening included serum sodium , calcium , potassium , aldosterone , renin , cortisol , catecholamines , and urinary metanephrines .
initial work - up revealed mild hypokalemia ( 3.4 meq / l ) and increased renin levels ( 7.7 ng / ml / h ) with normal aldosterone ( 22 ng / dl ) .
contrast - enhanced computed tomography of the abdomen demonstrated a 2.8 cm , well circumscribed , solid , hypoenhancing cortical lower pole lesion in the right kidney with 100 hounsfield units ( figure 1 ) .
the patient was counseled on options regarding radical nephrectomy and nephron - sparing surgery , as well as alternative for open or laparoscopic intervention .
she decided for laparoscopic partial nephrectomy and the procedure was accomplished without intra - operative complications .
histopathologic examination revealed a rare juxtaglomerular cell tumor known as reninoma ( figure 2 ) after minucious immunohistochemical analysis , which was negative for cytokeratin 35bh11 , ema , cd 34 , cd 56 , s-100 , chromogranin a , hmb-45 , wt-1 , and cd 31 ; and positive for aml ( areas ) , vimentin ( focally ) , actin hhf35 ( rare cels ) , and cd 117 ( focally ) .
patient s blood pressure normalized within 2 months of surgery ( systemic blood pressure < 120x90 mmhg ) , allowing withdrawn of all medications . 

figure 1contrast - enhanced computed tomography reveals a 2.8 cm , well circumscribed , solid , hypoenhancing cortical lower pole mass in the right kidney with 100 hounsfield units ( axial and coronal view ) . 
 

figure 2histological examination showing microscopic characteristics of juxtaglomerular tumor cells ( eosin and hematoxylin ) : tumor cells with mild nuclear atypia , inconspicuous nucleoli and pale ill - defined cytoplasm ; immunohistochemical study negative for chromogranin a , wt-1 , and cd 31 ; positive for aml ( areas ) , vimentin ( focally ) , and cd 117 ( focally ) . 

a 25-year - old female patient was referred for examination at our institution because of severe hypertension .
when she arrived to our office , she was already taking propanolol , hydrochlorotyazide and spironolactone for blood pressure control .
physical examination was essentially normal except for persistent high blood pressure ( systemic blood pressure = 150x100 mmhg ) .
laboratory screening included serum sodium , calcium , potassium , aldosterone , renin , cortisol , catecholamines , and urinary metanephrines .
initial work - up revealed mild hypokalemia ( 3.4 meq / l ) and increased renin levels ( 7.7 ng / ml / h ) with normal aldosterone ( 22 ng / dl ) .
contrast - enhanced computed tomography of the abdomen demonstrated a 2.8 cm , well circumscribed , solid , hypoenhancing cortical lower pole lesion in the right kidney with 100 hounsfield units ( figure 1 ) .
the patient was counseled on options regarding radical nephrectomy and nephron - sparing surgery , as well as alternative for open or laparoscopic intervention .
she decided for laparoscopic partial nephrectomy and the procedure was accomplished without intra - operative complications .
histopathologic examination revealed a rare juxtaglomerular cell tumor known as reninoma ( figure 2 ) after minucious immunohistochemical analysis , which was negative for cytokeratin 35bh11 , ema , cd 34 , cd 56 , s-100 , chromogranin a , hmb-45 , wt-1 , and cd 31 ; and positive for aml ( areas ) , vimentin ( focally ) , actin hhf35 ( rare cels ) , and cd 117 ( focally ) .
patient s blood pressure normalized within 2 months of surgery ( systemic blood pressure < 120x90 mmhg ) , allowing withdrawn of all medications . 

figure 1contrast - enhanced computed tomography reveals a 2.8 cm , well circumscribed , solid , hypoenhancing cortical lower pole mass in the right kidney with 100 hounsfield units ( axial and coronal view ) . 
 

figure 2histological examination showing microscopic characteristics of juxtaglomerular tumor cells ( eosin and hematoxylin ) : tumor cells with mild nuclear atypia , inconspicuous nucleoli and pale ill - defined cytoplasm ; immunohistochemical study negative for chromogranin a , wt-1 , and cd 31 ; positive for aml ( areas ) , vimentin ( focally ) , and cd 117 ( focally ) . 

secondary hypertension is a topic of particular interest for urologists worldwide , mainly because it has potential causes that may be recognized and definitively treated by their specialty .
patients with severe or refractory hypertension , sudden onset of hypertension , high blood pressure before 20 year - old or after 50 year - old , spontaneous hypokalemia , and unexplained renal dysfunction are situations in which complete workup for secondary hypertension and its related pathologies should be performed .
renovascular hypertension , primary hyperadosteronism , and pheocromocytoma are among those causes and should always be ruled out ( 1 - 4 ) .
although rare , chronic pyelonephritis and renal tumors as renin - producing tumors , nephroblastoma , hypernephroma , and renal cell carcinoma might also induce hypertension by different mechanisms and should be a part of the clinician diagnostic list .
the purpose of this article was to report and illustrate an interesting case where radiological investigation discovered a renal tumor as a possible cause of hypertension .
partial nephrectomy and pathological examination confirmed a juxtaglomerular cell tumor known as reninoma . the rationale is to provide the better care for patients with reversible causes of hypertension , diminishing their need for medications and cardiovascular risks . in our case ,
the above - mentioned diagnoses must be remembered so that appropriate investigation can be started .
renovascular hypertension is a condition in which patients have unilateral or bilateral renal artery stenosis and become normotensive when the vessel constriction is treated by angioplasty or surgery ( 1 ) .
doppler ultrasound is the most cost - effective study to screen renal artery stenosis , but it is dependent on the operator .
atherosclerotic disease is more common in older patients and has worse outcomes than fibromuscular dysplasia when treated by angioplasty ( 5 ) .
this case was very illustrative to remind us that approximately 5% of patients with hypertension have reversible secondary causes ( 6 ) . here
, we presented a patient with reninoma , an unusual cause of hypertension that mainly affects young individuals ( 7 - 9 ) .
the patient was successfully treated by minimally invasive laparoscopic nephron - sparing surgery , reducing the risk of loss of renal function and shorting hospital stay .
gottardo el al ( 8) reported the case of a 16-year - old hypertensive boy who presented with severe hypokalemia and markedly increased plasma renin activity .
abdominal ultrasonography and contrast - enhanced computed tomography revealed a 2 cm well - circumscribed , solid , hypoenhancing cortical lesion in the lower pole of the left kidney .
immunohistochemical ( ihc ) study comprised vascular markers ( cd31 and vimentin ) , neuroendocrine tumor marker ( cromogranin ) , mesothelioma marker ( wt1 ) , and hematopietic markers ( cd117 and aml ) .
all were negative or focally positive ( vimentin , cd117 ) and were used to exclude others rare renal tumors .
cases like reninoma do not have a specific pattern and ihc findings are inconsistent in the literature .
our diagnosis was based on microscopic characteristics such as tumor cells with mild nuclear atypia , inconspicuous nucleoli and pale ill - defined cytoplasm ( 8 , 10 ) .
mete et al ( 7 ) reported a similar case in which a 14-year - old boy with hypertension and preoperative diagnosis of reninoma underwent open nephron - sparing surgery for a 2 cm mass in right kidney .
the patient became normotensive postoperatively and follow - up intravenous urography showed bilateral normally functioning kidneys .
although image exams may find renal masses that could be associated to secondary arterial hypertension , there are other methods to prove such association .
wong et al ( 9 ) demonstrated the utility of both appropriate imaging studies and selective venous catheterization following provocative administration of an ace - i for diagnosis of reninoma
. we do not perform selective venous sampling routinely since it is a more invasive technique .
nevertheless , it may help in cases where all other diagnostic modalities have been performed and doubt regarding the specific cause of secondary hypertension persists .
general physicians , urologists and nephrologists are probably the most prone to seeing these patients in an office basis .
we hope that our case may help these and other physicians in their future practice .
laboratory testing and image workup may identify the cause of secondary hypertension and guide therapeutic options as in our case .
untreated secondary hypertension culminates in complications such as heart failure , kidney failure and stroke .
the detection of a secondary cause provides an opportunity to convert an incurable disease into a potentially curable one .
moreover , even when cure can not be achieved , early recognition and management may prevent target organ damage , reduce socioeconomic burden and improve quality of life ( 11 ) .
 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 . 
Main findings
Case hypothesis
Promising future implications
INTRODUCTION
Cases hypothesis and rational
DISCUSSION AND FUTURE PERSPECTIVES