Prenatal intrarenal neuroblastoma mimicking a mesoblastic nephroma: a case report.

Mesoblastic nephroma is by far the most frequent intrarenal fetal tumor. To the best of our knowledge, we report the first case of a newborn with an intrarenal neuroblastoma that was discovered prenatally. An intrarenal echogenic and homogenous mass was observed on routine prenatal ultrasonography, corroborated by magnetic resonance imaging, in a 30-week gestation fetus. A male weighing 3280 g was born with elevated blood pressure and cardiac failure. Postnatal ultrasound confirmed a left intrarenal tumor with microcalcifications and perirenal adenopathy. An open total left nephrectomy by laparotomy was performed. The pathologic study reported that the mass was an intrarenal neuroblastoma with local and regional invasion. Immediate postoperative urine analysis revealed a high level of vanillylmandelic acid, and blood samples showed high levels of normetanephrine. The purpose of this report is to demonstrate that prenatal intrarenal neuroblastoma can clinically and radiologically mimick a mesoblastic nephroma. High blood pressure, calcifications, and lymphadenopathy on ultrasound should raise the index of suspicion for a possible malignant process. Preoperative measurement of urinary vanillylmandelic acid (VMA) and metanephrines should be performed if the diagnosis is in doubt.

Low birth weight and its implication in renal disease.

It has been demonstrated that intrauterine growth retardation, defined as birth weight below the 10th percentile, gives rise to a reduction in nephron number. Oligonephropathy has been suggested to increase the risk for systemic and glomerular hypertension in adult life as well as enhance risk for expression of renal disease after exposure to potentially injurious renal stimuli. Diseases, such as diabetes, that damage the kidney, may enhance this risk. In addition, it has been hypothesized that the same factors affecting kidneys in utero also impact on pancreatic tissue development, thus predisposing infants of low birth weight to an increased risk for the subsequent development of diabetes and diabetic nephropathy, consistent with the so-called "thrifty phenotype" hypothesis. Impact of low birth weight on nondiabetic renal disease has also been shown in some studies. In the current scenario, chronic kidney disease is increasing all over the world and the major two causes are diabetes and hypertension. Once the issues are shifting from management of end-stage renal disease to prevention of chronic kidney disease, prevention of low birth weight is likely to be an issue for the nephrologists in future.

"Vascular neurofibromatosis" and infantile gangrene.

An 11-year-old boy with slowly progressive gangrene caused by vasculopathy similar to that of neurofibromatosis (NF) type 1 (NF I; von Recklinghausen disease [NFvR]) and a newborn girl with idiopathic gangrene with vascular changes resembling those of NFvR prompted the analysis of all 105 propositi with NF (NF I and NF II) evaluated between January 2, 1982, and December 31, 1986, at the genetics clinic of University of South Florida. They were analyzed for renal hypertension, symptomatic ischemia, and known vascular changes. One additional 27-month-old boy with NFvR was found to have extensive vascular changes with renal hypertension. The vasculopathy indicated asymmetric over/undergrowth of cellular and extracellular components of the vascular wall and implied dysregulation of the paracrine growth mechanism. Immunocytochemical studies of affected vessels were done only in the 11-year-old boy and showed positive neuron-specific enolase, S-100 protein, and glial fibrillary acidic protein (GFAP) reactions indicative of Schwann cell involvement. The vascular changes in children with NFvR are mostly asymptomatic; however hypertension secondary to renal artery stenosis and/or Moya-moya disease have been reported infrequently. Our patients with vasculopathies provoked thoughts in regard to the so-called vascular NF, its place in current NF nomenclature and classification, relationship to fibromuscular dysplasia (FMD), and possible role in infantile gangrene.

Neonatal hypertension from a unilateral multicystic dysplastic kidney.

Multicystic renal dysplasia is an extremely uncommon cause of hypertension in children and the few reported cases have not been of newborns. We report on a neonate in whom severe hypertension associated with elevated peripheral plasma renin resulted from a unilateral multicystic dysplastic kidney. Hypertension and plasma renin activity normalized after unilateral nephrectomy. No evidence of perfusion or excretory renal function in the dysplastic kidney was present on a radionuclide renal scan. This child demonstrates a relationship between hypertension and unilateral multicystic renal dysplasia.

[An unusual renal tumor, associating nephroblastoma, nephroblastomatosis, teratoma, and cystic dysplasia with arterial hypertension and secretion of alpha-fetoprotein]. / Une tumeur rénale inhabituelle, associant un néphroblastome, une néphroblastomatose, un tératome, une dysplasie kystique, à une hypertension artérielle et à une sécrétion d' alpha-foetoprotéine.

The authors report the case of a very unusual kidney tumour discovered in a newborn infant known to have abnormal dense and cystic structures in both kidneys already during the intra-uterine period as a result of antenatal echotomography. Severe hypertension developed on the 10th day of life, accompanied by the hypersecretion of angiotensin. Right nephrectomy of the multicystic and poorly functioning kidney resulted in the normalisation of blood pressure. A left lower polar nephrectomy for tumour finally gave a good result, with three years' follow-up. Histology of the right kidney revealed a nephroblastoma with cystic dysplasia, areas of nephroblastomatosis and the secretion of alpha-foetoprotein, in the nephroblastomatous tubular structures. On the left, there was a nephroblastoma associated with areas of nephroblastomatosis.

Congenital hypertension due to unilateral renal vein thrombosis.

A boy was found on the day of birth to have hypertension and radiological evidence of calcification of the left renal vein. Persistent hypokalaemia and hyper-reninaemia in the presence of a small left kidney and normal right kidney led to the decision to perform a left nephrectomy. The biopsied specimen showed old calcified renal vein thrombosis with accompanying medullary necrosis. Postoperatively hypertension resolved.