We report the long-term clinical results of conservative management of children with unilateral multicystic dysplastic kidneys (MCDK). Between 1989 and 2002, 43 children with MCDK detected by prenatal ultrasonography were prospectively followed. At birth, ultrasonography confirmed the prenatal findings in all cases. Patients underwent a radioisotope scan and micturating cystogram in order to confirm the diagnosis and to exclude other uropathies. Follow-up ultrasound (US) examinations were performed at 6-month intervals during the first 2 years of life and yearly thereafter. The mean follow-up time was 42 months (range 12-156 months). Two children developed hypertension during follow-up. In total 257 US scans were performed. The mean number of US scans per patient was 6 (range 3-10). US scans demonstrated partial involution of the MCDK in 30 (70%) cases and complete involution in 8 (19%). The absolute MCDK length remained almost unchanged in 5 children (11%). The estimated median time of complete involution of the MCDK was 122 months [95% confidence interval (CI)=86-158 months]. A total of 33 (76.7%) contralateral kidneys underwent compensatory hypertrophy, reaching a renal length above the 95th percentile during follow-up. The estimated median time for the occurrence of compensatory hypertrophy was 30 months (95% CI=15-45 months). In conclusion, the natural history of MCDK is usually benign but patients must have long-term follow-up with US scans and blood pressure measurements.

The objective of the work was to prepare an update on imaging methods for bone evaluation during childhood and adolescence. The text was based on original and review articles on imaging methods for clinical evaluation of bone mass in children and adolescents up to 20 years old. They were selected from BIREME and PUBMED by means of the following keywords: bone density; osteoporosis/diagnosis; densitometry; tomography; ultrasonography; magnetic resonance imaging; and radiogrammetry and published in Portuguese or English, in the last 10 years (2006-2016). The article was organized into topics with the description of peculiarities, advantages and disadvantages of each imaging method and their possible clinical applicability. Despite the emergence of new technologies, dual energy X-ray absorptiometry (DXA) remains the gold standard method for low bone mass diagnosis in all age groups. However, interpretation is complex in children and adolescents and demands skilled people. Quantitative computed tomography (QCT) [central QCT, peripheral QCT (pQCT) and high resolution-pQCT (HR-pQCT)] and magnetic resonance imaging (MRI) evaluate real bone density, but are not yet available for routine use. Quantitative bone ultrasound (QUS) shows good perspectives for its use in primary prevention actions. Automated radiogrammetry shows promise as a method able to flag individuals who might benefit from a complete bone assessment, but the clinical value of the measures still needs to be established.

The most common cystic lesion recognized antenatally is multicystic dysplastic kidney (MCDK). Recently, conservative management without nephrectomy has been advocated. The purpose of this study was to report our experience in the conservative management of unilateral MCDK. Between 1989 and 1997, 20 children with MCDK detected by prenatal ultrasonography (US) were prospectively followed. At birth, US confirmed the prenatal findings in all cases. All patients were submitted to radioisotope scans and a micturating cystogram. Follow-up US examinations were performed annually. Mean age at diagnosis during the prenatal period was 31 weeks of gestation (range 24-38). Median follow-up time was 33 months (range 7-91). Follow-up US was performed in 19 children; 13 (68%) showed partial involution, 4 (21%) complete involution, and 2 (11%) an increase in unit size. The mean age at complete or partial involution of the lesion was 18 months. No children developed hypertension or tumors, and all maintained normal growth. In conclusion, the natural history of MCDK is usually benign, and serial US examinations show that affected kidneys frequently show involution with time.

We report a case of transitory hypertension associated with unilateral multicystic dysplastic kidney (MCDK). A newborn girl with MCDK, detected by prenatal ultrasonography, was conservatively treated and has been followed for 18 months at the Pediatric Nephrourology Unit (HC-Belo Horizonte, Brazil). Arterial hypertension was observed at about 4 months of age and was associated with high levels of plasma renin activity and circulating angiotensin, and also with changes in renal Doppler ultrasonography. For these reasons, a nephrectomy was initially proposed. However, a spontaneous improvement of blood pressure levels was noticed at about 10 months of age. Serial Doppler ultrasonography showed involution of the affected renal volume and decreased arterial flow. The anatomical improvement was observed simultaneously with normalization of the peripheral renin and angiotensin values. The literature is reviewed regarding the relationship between hypertension and MCDK.

With the widespread use of obstetric echography the incidence of fetal hydronephrosis has been reported more frequently. Consequently, many uropathies have been detected in asymptomatic neonates. The authors report their experience with prenatally detected primary non-refluxing megaureter. Newborns with fetal hydronephrosis were investigated by ultrasonography and micturating cystourethrogram after the beginning of chemoprophylaxis. If primary megaureter was identified, after 1 month the children underwent 99tm-DMSA, diuretic 99tm-DTPA, and intravenous urography. Eight infants with primary megaureter (bilateral in 3 cases) were identified, for a total of 11 renal units for study. All children were submitted to non-operative management. We performed ultrasonography and diuretic 99tm-DTPA during follow-up, which lasted on average 75 months. The mean cross-sectional diameter of the dilated ureter was 13.6 mm during neonatal period, and reached 8.4 mm at the end of follow-up. The renal function and the diuretic renogram remained stable throughout follow-up. Two neonates presented transitory hypertension. Our results support the notion that conservative management is safe for primary megaureter detected in asymptomatic neonates, with most cases showing spontaneous regression during a prolonged follow-up.