Approach to the Patient: Reninoma

Reninoma: an unusual cause of growth failure

OBJECTIVES

Growth failure can result from various underlying causes, necessitating a thorough evaluation. Reninoma, a rare renin-secreting tumor, is an uncommon cause of hypertension, especially in paediatric patients, and has not been associated with growth failure until now.

CASE PRESENTATION

An 11-year-old girl presented with complaints of poor height gain, headaches, increased thirst, and vomiting. The evaluation revealed severe hypertension and hypokalemic alkalosis. Investigations indicated renin-dependent hypertension, and imaging identified a right renal mass. Renal venous sampling confirmed renin production from the tumor. A right open partial nephrectomy was performed, resulting in the normalization of blood pressure and improved growth. Over the following years, she achieved a significant catch-up growth, regaining her original height percentile and the target adult height.

CONCLUSIONS

This case adds to the limited literature on paediatric reninoma. It highlights a rare presentation of reninoma causing hypertension and growth failure in a child. The growth failure was likely due to hypokalemic alkalosis-induced low insulin-like growth factor 1 (IGF-1) levels, a mechanism not previously documented in paediatric reninoma cases. Surgical excision of the tumor led to normalization of blood pressure and metabolic alkalosis with significant growth recovery.

Unravelling a mystery of hypokalemic hypertension- a rare case report of a reninoma

BACKGROUND

Reninoma is a rare cause of secondary hypertension, which can be cured with surgery if identified early before any target organ damage occurs. It leads to hypokalaemia and hypertension and typically responds well to treatment with renin-angiotensin-aldosterone system blockers. However, confirmation of the diagnosis and the localisation of this rare culprit lesion can be challenging.

CASE PRESENTATION

We describe a case of young-onset hypertension in a 19-year-old girl due to a reninoma. She had resistant hypertension with marked hypokalaemia, which required exceedingly high doses of potassium supplements. Biochemical Investigations revealed secondary hyperaldosteronism. Thus, she underwent a renal angiogram to exclude a renovascular cause for her hypertension. While the renal artery anatomy was normal, there was an exophytic renal lesion in the lower pole of the left kidney. Hence, the diagnosis of a reninoma was suspected. She underwent renal vein sampling to confirm the functionality of the detected tumour, but the results were inconclusive. After a multidisciplinary discussion, based on the clinical evidence, the renal lesion was thought to be a reninoma and a partial nephrectomy was done, removing the lesion. Immediately following resection, her blood pressure and potassium normalised without further drug treatment, and the resected lesion was later confirmed to be a reninoma by histopathological examination.

CONCLUSION

In young people with hypokalemic hypertension, reninoma should be considered when the more common causes are excluded since prompt treatment with excision of the culprit lesion can cure hypertension and prevent associated morbidity and mortality.

Renovascular hypertension following by juxtaglomerular cell tumor: a challenging case with 12-year history of resistant hypertension and hypokalemia

BACKGROUND

Adolescents with secondary hyperaldosteronism often present with severe and treatment-resistant hypertension, along with hypokalemia. Renovascular hypertension is frequently caused by renal artery stenosis, primarily due to atherosclerosis and fibromuscular dysplasia (FMD). The presence of an accessory renal artery (ARA) is a common anatomical variation that can contribute to secondary renal vascular hypertension. However, FMD occurring in the ARA is a rare cause of renal vascular hypertension. Juxtaglomerular cell tumor (JGCT) represents a rare etiology of renal hypertension. The co-occurrence of the pathogenic ARA with JGCT is infrequently reported in the existing literature.

CASE PRESENTATIONS

This case study presents a young individual with a 12-year history of resistant hypertension, initially diagnosed with pathogenic ARA but later confirmed as JGCT 4 years later. Following surgery for JGCT, the patient experienced only temporary stabilization of blood pressure without anti-hypertensive medication. Stenosis of the ARA was definitively diagnosed one and a half years post-surgery, with FMD occurring on the ARA strongly suspected. The patient underwent balloon dilatation angioplasty 3 years later, leading to sustained blood pressure stability with the use of two medications.

CONCLUSIONS

The case study discussed herein involves a patient with resistant hypertension initially diagnosed with ARA but later determined to have late-onset JGCT and renal artery stenosis. It is imperative to consider atypical JGCT in young patients exhibiting resistant hypertension, hypokalemia, and hyperreninemia. Adequate management of renal artery stenosis is crucial in the management of hyperreninemic hypertension.

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.