Diagnostic challenges in patients with reninomas and extrarenal renin-producing tumours.

Renin-secreting tumours are rare causes of secondary hypertension and hypokalaemia. They are usually surgically curable, hence proper diagnostic work-up and tumour localisation is essential. In this paper, we present three Swedish patients recently diagnosed with renin secreting tumours, two with reninomas and one with an extrarenal renin-producing tumour, to illustrate diagnostic challenges. We also discuss the biochemical work-up, the pros and cons of different imaging techniques (computer tomography [CT], magnetic resonance imaging and [18F]fluorodeoxyglucose-positron emission tomography-CT), as well as how renal vein sampling (RVC) may contribute to localisation of the tumour.

A case of atypical reninoma with mild hypertension and normal plasma renin activity but elevated plasma renin concentration.

BACKGROUND: Reninoma is a rare, benign renal neoplasm. Typical clinical features include severe hypertension, secondary hyperaldosteronism, hypokalaemia and metabolic alkalosis caused by the overproduction of renin. CASE PRESENTATION: A 25-year-old lean Chinese woman with no family history of hypertension was hospitalized for stage 1 hypertension that gradually developed over two years. Endocrine investigation showed hyperreninemia without hyperaldosteronism and hypokalaemia. Interestingly, although the patient had an elevated plasma renin concentration (PRC), her plasma renin activity (PRA) was in the normal range. Abdominal contrast-enhanced computed tomography (CT) scanning revealed a solid, low-density, renal cortical mass with delayed enhancement. Selective renal vein sampling (SRVS) was performed, and a lateralization of the renin secretion from the left kidney was found. Enucleation of the tumour led to a rapid remission of hypertension and hyperreninemia. Based on pathological findings, the patient was diagnosed with reninoma. Immunohistochemical staining of the tumour was positive for Renin, CD34, Vimentin, and synaptophysin (Syn) and negative for somatostatin receptor 2 (SSTR2) and chromogranin A (CgA). CONCLUSIONS: Reninoma can present as mild hypertension without hyperaldosteronism and hypokalaemia. The clinical features of reninoma may depend on the degree of activation of the renin-angiotensin-aldosterone system (RAAS). PRC should be incorporated in the differential diagnosis of secondary hypertension.

JUXTAGLOMERULAR CELL CAUSE OF SECONDARY HYPERTENSION IN AN ADOLESCENT.

Reninoma (juxtaglomerular cell tumor) is a rare cause of renin-mediated hypertension. We reported a 18 year old woman with history of hypertension for 3 years. Laboratory findings showed severe hypokalemia and markedly increased levels of renin and aldosterone. Kidney ultrasonography, abdominal computed tomography and magnetic resonance imaging revealed a small mass in the middle region of the right kidney. The patient underwent nephron-sparing surgery; immunohistochemical results demonstrated typical features of reninoma. Postoperatively, blood pressure and potassium levels were normal at 1 month follow-up.

Usefulness of Magnetic Resonance Imaging in the Diagnosis of Juxtaglomerular Cell Tumors: A Report of 10 Cases and Review of the Literature.

Juxtaglomerular cell tumors (JCTs), a rare but potentially curable cause of hypertension, are difficult to diagnose because they may be missed or misidentified as a cyst by computed tomography (CT). Their magnetic resonance imaging (MRI) pattern has not been well described. We report the clinical, biological, and radiologic features of 10 patients with JCTs. Eight were women, and median age was 24.5 years. All had severe hypokalemic hypertension related to marked secondary hyperaldosteronism. Median plasma renin and aldosterone concentrations were 392 (minimum-maximum [min-max], 70.5-4,800) mIU/L and 1,490 (min-max, 671-2,492) pmol/L, respectively. Plasma prorenin concentration was 835.5 (min-max, 133-6,546) mIU/L. Median tumor size was 17.5mm. On CT, JCTs were spontaneously isodense, with little enhancement after contrast media injection. On MRI, JCTs were iso- (7/10) or hypointense (3/10) on T1-weighted images (WIs). On T2-WIs, JCTs were hypointense (2/10), isointense (4/10), or heterogeneously hyperintense (4/10). A thin peripheral "pseudo-capsule" (hypointense on T2-WIs) was observed in 6 of 10 cases. Contrast enhancement was low, slightly heterogeneous, and delayed. On diffusion-WIs, tumors were hyperintense with a restricted apparent diffusion coefficient. When hypertension with secondary hyperaldosteronism remains unexplained after CT, MRI of the kidney should be considered, especially for young women.

Approach to the Patient: Reninoma.

A reninoma is a functional tumor of afferent arteriolar juxtaglomerular cells that secretes the enzyme renin, leading to hyperactivation of the renin-angiotensin-aldosterone system. Reninoma is a potentially curable cause of pathological secondary hyperaldosteronism that results in often severe hypertension and hypokalemia. The lack of suppression of plasma renin contrasts sharply with the much more common primary aldosteronism, but diagnosis is often prompted by screening for that condition. The major differential diagnosis of reninoma is renovascular hypertension. Fewer than 200 cases of reninoma have been described. Reninomas have been reported across a broad demographic but have a 2:1 predilection for women, often of childbearing age. Aldosterone receptor blockade, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers offer effective medical management but are contraindicated in pregnancy, so surgical curative resection is ideal. The current optimal imaging and biochemical workup of reninoma and management approach (ideally, tumor excision with subtotal renal resection) are described.

Clinical features, laboratory findings and treatment of juxtaglomerular cell tumors: a systemic review.

Juxtaglomerular cell tumors (JGCTs) or reninoma are rare kidney tumors leading to secondary hypertension, and the non-specific clinical manifestations bring about challenges to the diagnosis. This study is to summarize the clinical features, laboratory findings, and treatment of JGCTs. The PubMed, EMBASE database, and manual search were utilized to find all cases, and 158 reports containing 261 patients were identified. Data on patients' demographics, clinical features, diagnostic methods, and treatment options were collected and analyzed. JGCTs occurred predominantly in female patients (female to male ratio, 2.1:1). The median age of patients was 25 years (IQR:18-34 years). Hypertension (97.24%) was the cardinal manifestation. Hypokalemia was reported in 78.71% (159/202) of subjects, and normal serum potassium accounted for 20.79% (42/202). In cases with assessed plasma renin activity (PRA) levels, the median PRA was 7.89 times the upper limit of normal (IQR:3.58-14.41), and 3.82% (5/131) of cases in the normal range. Tumors were detected in 97.8% (175/179) computed tomography (CT), 94.7% (72/76) magnetic resonance imaging (MRI), and 81.5% (110/135) ultrasound, respectively. For 250/261 patients undergoing surgical procedures, 89.14% (197/221), 94.94% (150/158), and 100% (131/131) of patients were restored to normal blood pressure, PRA, and serum potassium, respectively. JGCTs are commonly associated with hypertension, hypokalemia, and hyperreninemia, whereas patients with normotension, normokalemia, and PRA should be systematically pursued after drug-elution lasting for 2 weeks. CT and MRI are more sensitive imaging diagnostic methods. The blood pressure and biochemical parameters of most patients returned to normal after surgery.

Suspected primary hyperreninism in a cat with malignant renal sarcoma and global renin-angiotensin-aldosterone system upregulation.

A 14-year-old male castrated domestic medium-hair cat with diabetes mellitus was evaluated for vomiting, diarrhea, and anorexia. Two weeks before presentation, the cat had been diagnosed with congestive heart failure and started on furosemide. Initial diagnostic testing identified hypokalemia, systemic hypertension, and hypertrophic cardiomyopathy phenotype, and plasma aldosterone concentration was moderately increased. Abdominal ultrasound examination disclosed bilateral adrenomegaly and a right renal mass, and cytology of a needle aspirate of the mass was consistent with malignant neoplasia. The cat was treated with amlodipine and spironolactone. Because of the unusual presentation for hyperaldosteronism, a comprehensive profile of renin-angiotensin-aldosterone system (RAAS) peptides was performed. Results from multiple timepoints indicated persistently and markedly increased plasma renin activity and generalized RAAS upregulation. In addition to the lack of adrenal tumor, the markedly increased plasma renin activity was atypical for primary hyperaldosteronism. These clinical findings are suggestive of primary hyperreninism, a condition previously unreported in cats. The concurrent presence of a renal neoplasm suggests the possibility of a renin-secreting tumor.

Accurate lesion localisation facilitates nephron sparing surgery in reninoma patients: case report and discussion.

A 21-year-old female was referred with a suspected juxtaglomerular cell tumour (reninoma) in the superior pole of the left kidney. She underwent renal biopsy and renal vein sampling (RVS) to confirm the diagnosis. Following an uncomplicated laparoscopic partial nephrectomy, antihypertensive medications were ceased. Histopathology confirmed the diagnosis. Reninoma is a rare but reversible cause of secondary hypertension and should be considered along with primary hyperaldosteronism and pheochromocytoma when investigating hypertension in a young person. The subtle appearance of reninoma on imaging can necessitate other investigations to confirm the diagnosis. Definitive localisation is essential to prevent unnecessary loss of nephrons.

Spindle Cell Hemangioma and Atypically Localized Juxtaglomerular Cell Tumor in a Patient with Hereditary BRIP1 Mutation: A Case Report.

Spindle cell hemangioma is a benign vascular tumor typically occurring in the dermis or subcutis of distal extremities as red-brown lesions that can grow in both size and number over time. They can be very painful and potentially disabling. A family history of cancer or previous history may be relevant and must be taken into consideration. Juxtaglomerular cell tumor (reninoma) is an extremely rare cause of secondary hypertension diagnosed mostly among adolescents and young adults. Excessive renin secretion results in secondary hyperaldosteronism. Subsequent hypokalemia and metabolic alkalosis, together with high blood pressure, are clues for clinical diagnosis. Histological examination of the excised tumor leads to a definitive diagnosis. Reninoma is found in subcapsular localization, in most cases as a solitary mass, in imaging studies of kidneys. Exceptionally, it can be located in another part of a kidney. Both spindle cell hemangioma and reninoma are extremely rare tumors in children and adolescents. Herein, the authors present a case report of a patient with hereditary BRCA1 interacting protein C-terminal helicase 1 (BRIP1) mutation, spindle cell hemangioma, and secondary hypertension caused by atypically localized reninoma.

The Role of Real-Time Contrast-Enhanced Ultrasound in Guiding Radiofrequency Ablation of Reninoma: Case Report and Literature Review.

BACKGROUND: Reninoma is a rare renal endocrine tumor that can cause secondary hypertension, characterized by hypertension, hypokalemia, high renin and aldosterone with normal aldosterone renin ratio (ARR), and occurs more in young female. Mainstream treatment option is surgery, but is less suitable for small or deep lesions, which makes ablation a promising alternative. CASE PRESENTATION: Two young female with typical manifestations of reninoma, including hypertension, hypokalemia, high renin, high aldosterone and normal ARR, were treated successfully with real-time contrast-enhanced ultrasound guided radiofrequency ablation, and contrast-enhanced ultrasound was also performed before and after treatment for diagnosis and postoperative assessment. Afterward, their blood pressure and laboratory tests became normal and remained steady during the follow-up of 32 and 6 months, respectively. CONCLUSION: Contrast-enhanced ultrasound guided radiofrequency ablations is a promising alternative for reninoma treatment with comparable safety and efficacy with surgery, and has advantages especially in small or deep lesions.

[A rare cause of hypertension with hypokalemia: A case of reninoma]. / Une cause rare d'hypertension artérielle avec hypokaliémie : un cas de réninome.

Reninoma or juxtaglomerular cell tumor is a rare usually benign renal renin secreting tumor. We report the case of an 18-year old woman, without any medical history, investigated in our hospital's emergency department for a bilateral papilledema. Ambulatory ophthalmological investigations were performed because of a newly occurring blurry vision, associated with diffuse headaches. Cerebral mRI and lumbar puncture recommended by the ophthalmologist and neurologist excluded intra-cranial hypertension. The patient presented with severe hypertension. Laboratory values showed hypokalemia, compensated metabolic alkalosis and microalbuminuria. During the hospital stay, she developed AKIN 1 acute renal injury. Ultrasound revealed a tissular cystic lesion of the superior pole of the right kidney. Abdominal mRI confirmed the lesion and raised suspicion for a renal cell carcinoma without calicial or vascular invasion. Plasma renin value was >500 mUI/L with normal values for plasma aldosterone. Renal biopsy diagnosed a juxtaglomerular cell tumor. After an aggressive initial treatment, hypertension remained well controlled with spironolactone only, finally allowing for withdrawal of all antihypertensive medications. Robot-assisted laparoscopic partial nephrectomy was performed. Studies of the operative specimen confirmed the diagnosis of benign reninoma. Clinical follow-up showed complete resolution of clinical and biological parameters.

Juxtaglomerular Cell Tumor With Atypical Pathological Features: Report of a Case and Review of Literature.

Juxtaglomerular cell tumor (JGCT) is a rare renal tumor with a predominantly benign clinical course. It affects young adults, who often present with hypertension, hypokalemia, and hyperaldosteronism. The tumor cells are round to spindle-shaped with occasional mild to moderate atypia, but mitotic figures are usually absent. Surgical resection is the treatment of choice. Typically, the blood pressure and renin levels normalize after removal of the tumor. Rare cases of metastatic and recurrent JGCT have been reported including cases with vascular invasion. These cases typically occur in older adults and present with larger tumor size (9-15 cm). We report a case of JGCT, 5.5 cm in greatest dimension, with atypical pathological features including invasion of the renal vein, lymphovascular invasion, and significant pleomorphism with rhabdoid morphology, along with a brief review of the literature.

Robot-Assisted Partial Nephrectomy for Treatment of Juxtaglomerular Cell Tumor of the Kidney: A Case Report.

Background: A juxtaglomerular cell tumor (JGCT), or a reninoma, is a rare renal tumor that can cause secondary hypertension. This is the first reported JGCT that was resected through robotic surgery. Case: We present a case of a 27-year-old female patient with 1.35-cm-sized JGCT in the lower pole of the right kidney. We effectively removed a JGCT through robot-assisted partial nephrectomy without any complications. Conclusion: The robot-assisted partial nephrectomy procedure could be a suitable choice for JGCT resection.

Juxtaglomerular Cell Tumor: Reviewing a Cryptic Cause of Surgically Correctable Hypertension.

Juxtaglomerular cell tumor (JGCT), or reninoma, is a typically benign neoplasm generally affecting adolescents and young adults due to modified smooth muscle cells from the afferent arteriole of the juxtaglomerular apparatus. Patients experience symptoms related to hypertension and hypoka-lemia due to renin-secretion by the tumor. MRI, PET, CT, and renal vein catheterizations can be used to capture JGCTs, with laparoscopic ultrasonography being most cost-efective. Surgical removal is the best option for management; electrolyte imbalances are a potential complication which may be assuaged via pre-surgical administration of aliskiren, a renin inhibitor. Considering the vast etiology for hypertension and rarity of JGCT, the diagnosing physician must have a high index of suspicion for JGCT. Early recognition and management can help prevent cardiovascular or pregnancy complications and fatalities, vascular invasion and metastasis, improve quality of life, and limit socioeconomic liabilities. Herein we review the epidemiology, genetics, histopathol-ogy, clinical presentation, and management of this rare condition. The impact of genetics on prognosis warrant further research.

Reninoma coexisting with adrenal adenoma during pregnancy: A case report.

Reninoma is a rare form of secondary hypertension. The present study reported a case of reninoma that coexisted with an adrenal adenoma in a young female with secondary hypertension during pregnancy. The patient, a 31-year-old female exhibiting hypertension for >1 year, developed a mass in the right adrenal gland, which was detected by an ultrasound scan in the 33rd gestational week. In addition, a well-defined solid mass on the left kidney was detected by a magnetic resonance imaging scan1 month subsequent to the termination of the pregnancy. The blood pressure (BP) of the patient did not change subsequent to the laparoscopic right adrenalectomy. The patient subsequently underwent laparoscopic left partial nephrectomy 2 months later. The BP levels demonstrated a significant reduction from 177/115 to 125/80 mmHg in the same day postoperatively, and stabilized to be within the normal range. The BP level of the patient remained within the normal range subsequent to a 6-month follow-up. Pathological analysis revealed reninoma on the left kidney. The present study aimed to provide information for radiologists who may encounter this type of benign tumor in the future, which exhibits elevated BP levels.

Laparoscopic nephro-sparing surgery of juxtaglomerular cell tumor in a child.

OBJECTIVE: To report a case of juxtaglomerular cell tumour of the kidney (reninoma) in a child treated with laparoscopic nephron-sparing surgery. PATIENTS AND RESULTS: A 14-year-old girl was incidentally found to have hypertension (180/114 mmHg) at the time of adenotonsillectomy. Pre-operative investigations revealed a plasma renin level of 225.9 ng/dl (4.4-46), normal aldosterone, cortisol and urinary catecholamine. Abdominal ultrasound detected a 1.9 × 1.5-cm hypoechoic lesion in the right kidney lower pole; CT scan confirmed the presence of a 1.5-cm, circumscribed, solid, hypoenhancing cortical lesion in the right lower pole. Laparoscopic nephron-sparing surgery was accomplished by clamping the renal artery for 30 min; after excision, the tumour bed was closed using barbed V-loc sutures. The procedure was completed laparoscopically in 150 min with no peri-operative complications. The patient was discharged home on day 4 postoperatively. Histology confirmed the diagnosis of a juxtaglomerular cell tumour that was completely excised. The J-J stent was removed 1 month later. At follow-up, the patient's blood pressure was normalized and medications were stopped. A DMSA scan confirmed 36% residual right kidney function. CONCLUSION: Laparoscopic nephron-sparing surgery should be considered in children with juxtaglomerular tumours. This technique allows prompt recovery with preservation of significant renal function.

Spermatic venous sampling in assisting the diagnosis of reninoma: One case report and literature review / 中华内分泌代谢杂志

To investigate the renal venous and spermatic venous sampling in assisting the diagnosis of reninoma. The case of reninoma was retrospectively reviewed together with the literature review of reninoma diagnosed with renal venous and spermatic venous sampling. A young patient with hypertension and headache was admitted to our hospital. Laboratory test showed high plasma renin concentration (>500 mIU/L), and enhanced computed tomography(CT) in the upper abdomen showed a mass in left inferior renal pole. The concentration of renin in the left spermatic vein was significantly higher than that in renal veins and branches, and peripheral vein, which was considered the left reninoma possibility. The left renal mass was resected surgically and pathologic exam revealed reninoma. The renin level and the blood pressure recoveried normal after operation.The literature reported that the positive rate of renal vein segmental blood collection for locating renin tumor was only 8.3%-64%. The possible reason was that reninoma usually located in the renal cortex, and the tumor blood might be collected by renal capsule vein instead of renal vein. In fact, the renal capsule vein intersects with the lateral division of the spermatic vein, but there have been no reports about the localization of reninoma by spermatic vein sampling. Since renin secreted by reninoma may go into the spermatic vein through renal capsule vein, it should be noted that spermatic venous blood should be collected simultaneously in renal vein sampling when locating reninoma.

Anesthetic management for percutaneous computed tomography-guided radiofrequency ablation of reninoma: a case report.

A reninoma is an uncommon, benign, renin-secreting juxtaglomerular cell tumor that causes secondary hypertension in young patients. This hypertension is treated by tumor resection. Except for increased levels of plasma renin and angiotensin I and II, the other physical and laboratory examinations and electrocardiographs were within normal limits upon admission of a 19-year-old woman with a reninoma. For percutaneous computed tomography-guided radiofrequency ablation, general anesthesia was induced by thiopental sodium and rocuronium bromide and maintained with servoflurane (2-4 vol%) and oxygen. The operation ended uneventfully in hemodynamic stability. However, the patient complained of dizziness while sitting 5 hours after the operation, and hypotension was diagnosed. After aggressive normal saline (1 L) infusion over 30 min, the hypotension was corrected and the patient recovered without any other surgical complications. Here, we report the anesthetic management of a patient who underwent percutaneous computed tomography-guided radiofrequency ablation for reninoma destruction, particularly focusing on postoperative hypotension.

Reninoma: an uncommon cause of Renin-mediated hypertension.

Reninoma (juxtaglomerular cell tumor) is a rare cause of renin-mediated hypertension. Reninomas are usually diagnosed in adolescents and young adults with occasional reports in younger children. Patients typically present with a long history of headaches leading to a diagnosis of severe hypertension that responds well to antihypertensive treatment targeting the renin-angiotensin-aldosterone system. The clue to clinical diagnosis is the presence of hypokalemia and metabolic alkalosis on the first blood sample drawn before any treatment is instituted. Elevated blood levels of renin and aldosterone confirm the clinical suspicion of renin-mediated hypertension. Diagnostic imaging is employed to identify the source of excessive renin production. While renal ultrasound can miss reninoma, contrast CT or magnetic resonance imaging of the kidneys are diagnostic modalities of choice leading to the correct diagnosis. Renal vein renin sampling with lateralization might help to identify the site of excessive renin production. Nephron-sparing surgery is curative with maintenance of normal blood pressure after discontinuation of antihypertensive medications in the majority of patients. In this paper, we present the case of reninoma in an adolescent girl emphasizing clinical presentation, diagnostic evaluation, and medical and surgical treatment of this rare tumor. We also discuss important points in the management of children presenting with renin-mediated hypertension.

Reninoma presenting as cardiac syncope.

Reninoma, a renin-secreting tumor of the juxta-glomerular cells of the kidney, is a rare but surgically treatable cause of secondary hypertension in children. We report a case of reninoma presenting as cardiac syncope with long QTc on electrocardiogram due to hypokalemia.