Diagnostic ultrasound ( PDFDrive )

1816 PART V Pediatric Sonography
A B C
FIG. 52.57 Multicystic Dysplastic Kidney (MCDK). (A) and (B) Longitudinal and transverse gray-scale images of a 27-week gestational age
fetus depict the presence of multiple cysts of varying size surrounded by echogenic cortex. (C) Longitudinal gray-scale image of a different patient
at birth shows near-complete replacement of the left kidney by numerous cysts. See also Video 52.7.
A
B
FIG. 52.58 Nephronophthisis. Neonate With Homozygous NPH3 Mutations Associated With Anuria and Pulmonary Hypoplasia. (A)
and (B) Longitudinal gray-scale images of the right and left lanks, respectively, reveal echogenic parenchyma with loss of corticomedullary differentiation
and multiple cysts located throughout both kidneys.
age and have polydipsia and polyuria and decreased urinary
concentration. A slowly progressive decline in renal function
typically occurs. An exception to this clinical presentation is the
infantile variant, usually a result of mutation in the NPHP2 or
NPHP3 gene, which is seen in patients in the irst few months
of life with renal insuiciency and hypertension, and rapid
progression to end-stage renal disease. 191 he kidneys are normal
in size or small, except in the infantile form, in which they are
enlarged. 192 On ultrasound, the kidneys are echogenic with
decreased corticomedullary diferentiation (Fig. 52.58). Cysts
may be observed at the corticomedullary junction.
Medullary cystic kidney disease is an autosomal dominant
tubulointerstitial disorder that usually manifests in the third to
sixth decades of life. As with NPHP, there may be a history of
polydipsia and polyuria, and urinary concentrating ability is
decreased. Type 1 disease is caused by heterozygous mutations
in the MUC1 gene. Type 2 disease is caused by heterozygous
mutations in the uromodulin gene. 164 On ultrasound, the
kidneys are normal to small in size, and oten echogenic. Similar
to NPHP, cysts can occur at the corticomedullary junction
(Fig. 52.59).
Congenital Renal Cysts
Tuberous Sclerosis and Von Hippel–Lindau
Disease
Although renal cysts occur in many syndromes, two of the most
common are tuberous sclerosis and Von Hippel–Lindau Disease.
Tuberous sclerosis is an autosomal dominant disease consisting
of mental retardation, epilepsy, adenoma sebaceum, multiple
ectodermal lesions, and mesodermal hamartomas. Renal lesions
are present in more than 40% of patients and include cysts,
which can be multiple and resemble ADPKD with renal enlargement
(Fig. 52.60).
Von Hippel–Lindau disease is an autosomal dominant
disorder characterized by the formation of tumors and cysts in
many diferent organs throughout the body. Renal cysts and
renal cell carcinoma are common visceral manifestations of this
disorder, with the latter a signiicant cause of mortality. 193
Acquired Cysts
Patients with chronic renal failure, especially those receiving
long-term dialysis, oten develop renal cysts (Fig. 52.61).