Radiological and pathologic findings of fetal renal cystic diseases and associated fetal syndromes: A pictorial review Poster No.: C-2835 Congress: ECR 2010 Type: Educational Exhibit Topic: Pediatric Authors: S. Moon, J. Y. Cho, S. H. Kim, Y. H. Lee, M. J. Song, M. H. Moon; Seoul/KR Keywords: fetal, cystic renal disease, ultrasonography DOI: 10.1594/ecr2010/C-2835 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 13
Learning objectives The purpose of this exhibition is to assess the prenatal ultrasound and pathological findings of variable renal cystic diseases. Background There are variety of renal cystic diseases of the fetus (e.g., multicystic dysplastic kidney, autosomal recessive polycystic kidney, autosomal dominant polycystic kidney, obstructive cystic renal dysplasia, simple renal cyst, medullary cystic disease, and syndromes accompanied with renal cystic diseases). It is not easy to make differential diagnosis in antenatal ultrasonography. However, early detection and differential diagnosis are very important, because prognosis and antenatal managements are different in each renal cystic disease. The purpose of this exhibition is to assess the prenatal ultrasound and pathological findings of variable renal cystic diseases. Imaging findings OR Procedure details *Multicystic Dysplastic Kidney Multicystic dysplastic kidney(mcdk) is characterized by disturbed differentiation of nephrogenic tissue and the presence of multiple cysts of varying sizes. It is associated with ureteral or pelviureteral atresia, and a non-functioning kidney. Typically, MCDK is a unilateral disorder. On the other hand, the bilateral condition is incompatible with life. Affected children are stillborn or die in the early postnatal period. 1. Unilateral MCDK Page 2 of 13
Fig.: 1. US findings of unilateral MCDK A & B. There are multiple variable size cysts in the left kidney. The cysts are not communicating with each other. Normal parenchyma and pelvocalyceal system are invisible. Fig.: 2. Pathologic findings of MCDK A. On the cut surface photography, there are well defined multiple cysts in the left kidney. B. Photomicrography shows multiple cysts (arrows) and increased connective tissue. There is no normal glomerulus. 2. Bilateral MCDK Page 3 of 13
Fig.: 3. US findings of bilateral MCDK A. There are multiple variable size cysts in both kidneys without normal parenchymal echo. The amount of amniotic fluid is markedly decreased. B. On the power Doppler US, there is no renal arterial flow from the aorta. 3. Segmental MCDK Fig.: 4. Segmental MCDK in the duplicated kidney A. Axial image of the upper pole level shows normal shape of the upper pole of the right kidney. B. Axial image of the lower pole level shows several cysts (small arrows) in the right kidney. Page 4 of 13
C. Longitudinal image reveals normal upper pole pelvis (arrow) and segmental MCDK in the lower pole. 4. MCDK with UPJ Obstruction Fig.: 5. US findings of MCDK with UPJ obstruction A. There is a large cyst in the right side of abdomen due to markedly dilated right renal pelvis. There are multiple cysts (arrows) in the left kidney. B. Longitudinal image shows typical findings of MCDK in the left kidney. *Autosomal Recessive Polycystic Kidney Autosoaml recessive polycystic kidney (ARPCK) is an inherited autosomal-recessive disease, manifesting variable clinical expression dependent on the degree of renal and hepatic involvement. ARPKD is confined to childhood, is bilateral and relatively symmetric. The nephrons are normal in number and configuration. Both kidneys are enlarged, but a smooth contour is maintained. Page 5 of 13
Fig.: 6. US and autopsy findings of a fetus with ARPCK References: S. Moon; Radiology, Seoul National University Hospital, Seoul, KOREA, A & B. Both kidneys are enlarged with increased parenchymal echogenicity. Renal pelvis is collapsed. The volume of amniotic fluid is markedly decreased. C. Photography of the cut surface shows innumerable tiny cysts in the enlarged kidney. D. Photomicrography shows multiple dilated collecting tubules with cystic changes (arrows). The glomeruli have normal configuration. *Autosomal Dominant Polycystic Kidney Autosomal dominant polycystic kidney (ADPCK) is a late-onset disorder characterized by progressive cyst development and bilaterally enlarged kidneys with multiple cysts. Cyst formation begins in utero from any point along the nephron. Occasionally, numerous tiny cysts in fetuses affected with ADPCK shows diffusely increased renal echogenicity due Page 6 of 13
to multiple interfaced of numerous tiny cysts which are usually smaller than the limit of sonographic resolution. Fig.: 7. US findings of ADPCK A & B. Coronal and axial image show mildly enlarged both kidneys with increased cortical echogenicity and prominent cortico-medullary differentiation. There is no definable renal cyst. The volume of amniotic fluid is normal. C. US reveals the involvement of ADPCK in the paternal kidneys. D. Postnatal US demonstrates several cortical cysts (arrow). *Obstructive Cystic Dysplasia The pathogenesis of cystic dysplasia associated with obstructive uropathy is still unclear. Bladder outlet obstruction such as posterior urethral valve is common cause. According to the recent theory, fetal urinary tract obstruction may cause urine retention in functioning Page 7 of 13
nephrons and lead to glomerular cysts in the nephrogenic zone. Expansion glomerular cysts with tubular dilatation (cysts) disturbs the subsequent nephron induction and may contribute to the abnormal development of fetal kidneys. Fig.: 8. US findings of obstructive cystic dysplasia due to posterior urethral valve A. US at 14wk shows markedly enlarged urinary bladder due to bladder outlet obstruction, which is the most common cause of obstructive dysplasia. B. US at 21wk demonstrates cortical cysts and increased parenchymal echogenicity, suggesting cystic dysplasia. The renal pelvis is dilated. Fig.: 9. Pathological findings of obstructive cystic dysplasia A. Photography of the cut surface shows marked hydronephrosis in the left side of horseshoe kidney with parenchymal thinning. Page 8 of 13
B. Photomicrography shows multiple subcapsular cysts (arrows). *Simple Renal Cyst Fig.: 10. US findings of a fetus with simple renal cyst A. Longitudinal image of left kidney shows a well defined cyst (arrow) in the upper pole. The size and echogenicity of the kidney is normal. B. Postnatal US image also shows a well defined cyst (arrow) in the upper pole also. The other part of the kidney is normal with normal renal function. *Fetal Syndromes with Renal Dysplasia 1. Meckel-Gruber syndrome Meckel-Gruber syndrome is characterized by the triad of occipital encephalocele, large polycystic kidneys, and postaxial polydactyly. Failure of mesodermal induction has been suggested as the cause of Meckel-Gruber syndrome. Oligohydramnios that results from dysplastic kidneys leads to fetal pulmonary hypoplasia. Page 9 of 13
Fig.: 11. US findings of Meckel-Gruber Syndrome A. Coronal image of a fetal abdomen shows multiple cysts in both kidneys, suggesting multicystic dysplasia. The amount of amniotic fluid is markedly decreased. B. Axial image of fetal head shows a protruding cyst (arrow) in the occipital area with disruption of occipital bone, which is consisted with occipital encephalocele. 2. Jeune syndrome (Asphyxiating thoracic dysplasia) Jenue syndrome (Asphyxiating thoracic dysplasia) is an uncommon autosomal recessive skeletal disorder characterized by a small thorax, varying degrees of rhizomelic brachymelia, polydactyly, pelvic abnormalities, and renal anomalies. Page 10 of 13
Fig.: 12. US and autopsy findings of Jeune Syndrome A & B. Longitudinal and axial images of fetal kidneys show mildly increased size and echogenicity of both kidneys. C. Sagittal image of the fetus shows narrow fetal thorax (T) compared with the abdomen (A). D. Photograph of the dead fetus shows narrow thorax and short extremities, suggesting asphyxiating thoracic dysplasia. *Medullary Cystic Disease Medullary cystic kidney disease (MCKD) and nephronophthisis (NPH) are inherited diseases with similar renal morphology characterized by bilateral small corticomedullary cysts in kidneys of normal or reduced size and tubulointerstitial sclerosis leading to endstage renal disease (ESRD). Page 11 of 13
Fig.: 13. US & autopsy findings of medullary cystic disease A & B Coronal image shows mildly increased parenchymal echogenecity of enlarged both kidneys. The amniotic fluid is markedly decreased due to impairment of renal function. C. Photography of cut surface shows multiple tiny cysts in the renal medulla. D. Photomicrography shows innumerable cysts in the renal medulla. Conclusion Page 12 of 13
On prenatal US, detection and differential diagnosis of fetal renal cystic diseases should be meticulously examed because of different prognosis and antenatal management in each renal cystic disease. Personal Information Moon, Sung Kyoung, MD. Department of Radiology, Seoul National University Hospital, Seoul, Korea E-mail: radmsk@hotmail.com References Fong, KW., et al. Fetal renal cystic disease: sonographic-pathologic correlation. AJR 1986;146:767-73. Hayden, CK., et al. Renal cystic disease in childhood. Radiogrphics 1986;6:97-116. Friedmann, W., et al. Perinatal differential diagnosis of cystic kidney disease and urinary tract obstruction: anatomic pathologic, ultrasonographic and genetic findings. Eur J Obstet Gynecol Reprod Biol. 2000;89:127-33. Glazer, GM., et al. The varied sonographic appearance of the urinary tract in the fetus and newborn with urethral obstruction. Radiology. 1982;144:563-568. Nagata, M. et al. Pathogenesis of dysplastic kidney associated with urinary tract obstruction in utero. Nephrol Dial Transplant. 2002;17 Suppl 9:37-38. Chen, CP., et al. Prenatal Diagnosis of Asphyxiating Thoracic Dysplasia (Jeune Syndrome). Amer J Perinatol 1996;13:495-498. Page 13 of 13