congenital renal anomalies

CONGENITAL RENAL ANOMALIES

DEVELOPMENT

Intermediate mesoderm Pronephros Mesonephros Metanephros

5th week - definite kidney begins to form

Metanephros Metanephric diverticulum

(Ureteric bud) Metanephric blastema

CLASSIFICATIONAbnormalities

of Number

Abnormalities of Position

Abnormalities of Renal

Fusion

Abnormalities of Renal

Vasculature

Abnormalities in Structure

Renal AgenesisSupernumerary Kidney

Rotational AbnormalitiesRenal Ectopia

Horseshoe KidneysCrossed Fused Ectopic Kidney

Fetal LobationRenal Tissue (Pseudo) MassesCongenital Cystic DiseasesMesoblastic NephromaNephroblastomatosis

Renal agenesis (abn in number)

1:1000 M>F

Failure of formation of ureteric bud

Absent ureter and hemitrigone

Renal agenesis

IVU APPEARANCE

10% absence of I/L adrenal (Lying down adrenal sign)

Associated ipsilateral urogenital anomalies common

Neonate with

Pulmonary hypoplasia

Absent renal arteries

disc shaped adrenal

Bilateral – POTTER’S SYNDROMEFatal

Causes non visualization of Kidney in U/L Renal Fossa

Ectopic / cross fused Nephrectomy Severely atrophic kidney

Supernumerary kidney

Rare

formation of two ureteral buds on one side

Bifid/ separate ureter

3D volume rendering

ABNORMALITIES OF POSITION

Nonrotation and Malrotation

Ectopia

Underascent

Overascent

Normal rotation – 90 degree medial rotation of PUJ

Non rotation -Hallmark “ Some of the calyces will be located medial to the PUJ “

Malrotation- Reverse or over-rotation

Renal Ectopia

Normal renal ascent – caudal to cranial

1 in 1000 M:F = 1.5:1

Location – Pelvis, iliac fossa

Anomalous blood supply

Ectopic kidney on USG

• Trauma • PUJ obstruction / VUR• Decreased function • Stone formation

Conditions

affecting the

Ectopic kidney

Overascent of kidney

Underascent >>> overascent

Usually below the diaphragm

Very rarely – Thoracic Kidney

Abnormalities of Renal Fusion

Horseshoe Kidneys

Crossed Fused Ectopic Kidney

(a) Unilateral fused kidney (inferior ectopia). (b) Sigmoid or S-shaped kidney. (c) Lump kidney. (d) L-shaped kidney. (e) Disc kidney. (f) Unilateral fused kidney (superior ectopia)

Horseshoe kidney

1 in 400 M:F = 2:1

Two kidneys joined by isthmus (parenchymal/fibrous )

Kidney is low lying

IVP APPEARANCE

Malrotated kidneys

Lower poles are directed infero medially

USG

abnormally rotated

inferiorly located kidney

poor visualisation of the inferior

pole

Associated conditions:

At risk for traumaPUJ obstruction/Duplication/Stone formation Medullary sponge kidneyWilms tumorTurner / Ellis-Van Crewald syndrome

Cross fused renal ectopia

Uncommon condition

M > F Kidney crosses midline

Types

(a) Unilateral fused kidney (inferior ectopia).

(b) Sigmoid or S-shaped kidney. (c) Lump kidney. (d) L-shaped kidney. (e) Disc kidney. (f) Unilateral fused kidney (superior

ectopia)

Pancake kidney /disc kidney/ lump kidney

Cross Fused Ectopic

Abnormalities of Renal Vasculature Failure of involution of arteries during

ascent

25 % adult population

Common with pelvic / horseshoe kidney

Important for preoperative evaluation

Abnormalities in Structure

Fetal Lobation

Renal Tissue (Pseudo) Masses

Congenital Cystic Disease

Mesoblastic Nephroma

Nephroblastomatosis

Persistent Fetal lobations

5 % of adult patients Can be mistaken for other parenchymal

disorders

Diferentiating features Parenchymal thickness >14 mm Indentation must be smooth and regular Centering of calyces

Renal pseudo-tumor

Hypertrophied renal columns of bertini

Other Conditions that mimics Pseudo tumor

Dromedary Hump

Duplication Anomalies

Pyelonephritis

Congenital Cystic Diseases

Multicystic dysplastic kidney (MDK)

Autosomal recessive polycystic kidney disease (ARPKD)

Medullary sponge kidney (MSK)

Multilocular cystic nephroma (CN)

Calyceal diverticulum.

Multicystic dysplastic kidney (MDK)

1 in 4500

Unilateral, non functioning kidney

USG

left kidney is small and composed of cysts with calcification

compensatory hypertrophy of the right kidney.

MR Urography – Left sided MCKD

POLYCYSTIC KIDNEY DISEASE

AUTOSOMAL RECESSIVE

Commonly presents at birth (perinatal, neonatal, infantile, juvenile)

Renal parenchyma is replaced by numerous tiny cysts (1-8mm).

Oligohydramnios and potter’s syndrome

perinatal type: most common oligohydramnios and pulmonary hypoplasia 75% have death within 24 hours of delivery minimal hepatic fibrosis

neonatal type:

infantile type:

juvenile type: portal hypertension with splenomegaly and portosystemic varices

USGAntenatal Usg : Oligohydramnios

1. Enlarged echogenic kidney with

loss of CMD.

2. Renal outline is maintained

Splenomegaly

Ascites

CT APPEARANCE

IVP – Striated nephrogram

Contrast in preserved tubules next to unopacified tubules

Esophageal varices with the juvenile form of autosomal recessive polycystic kidney disease.

AUTOSOMAL DOMINANT PKD

20 – 40 yrs of age.

Asymptomatic in early stage

Numerous cysts of varying sizes


A: Early disease: numerous small intrarenal cysts.

B: Advancing disease: Enlarged kidneys and multiple cysts of varying sizes throughout cortex and medulla.

IVP APPEARANCE- SWISS CHEESE NEPHROGRAM

multiple well defined non perfused areas (Cysts)

Streched out calyces


Nonenhanced CT scan (A) shows bilateral nephromegaly. Contrast-enhanced CT scan (B) reveals large renal cysts with enhancing residual parenchyma between the cysts.


Significant hepatomegaly caused by liver cysts in a 47-year-old woman with autosomal dominant polycystic kidney disease.

Associations• Cysts in liver (50%),pancreas, brain, spleen ,ovaries and

testes.

• Berry aneurysm 15%

• Aneurysms of coronary arteries and aorta.

• Valvular heart disease

• Colonic diverticuli

MEDULLARY SPONGE KIDNEY

Due to ectasia (fusiform or cystic) of collecting duct with in renal parenchyma.

Usually B/L may be unilateral or segmental. Benign , asymptomatic. Weak association with Wilm’s disease Pheochromocytoma Horseshoe kidney Hemihypertrophy


Medullary sponge kidney. Intravenous urogram shows a paintbrush like appearance produced by cystic dilatation of medullary collecting ducts (arrows)

IVU


USG

Medullary part of collecting duct -dysplastic and dilated

80% -medullary nephrocalcinosis

Greatly increased renal medullary echogenicity

NCCT -clusters of calcification around the corticomedullary junction of both kidneys.

Nephrocalcinosis Albrights calcinosis

1. medullary nephrocalcinosis: 95%2. cortical nephrocalcinosis: 5%

Causes of medullary nephrocalcinosis

hyperparathyroidism medullary sponge kidney renal tubular acidosis (type 1) hypervitaminosis D milk-alkali syndrome sarcoidosis

Multilocular Cystic Renal Tumor

bimodal age distribution

M:F = 2:1

well-circumscribed, multiloculated, cystic renal mass.

cysts of varying sizes separated by septa.

Diiferentiate it from MCKD

“ Enhancement of surrounding comrpressed renal parencyma is present in loculated tumor abdent in MCKD

Nephroblastomatosis

multifocal areas of persistent nephrogenic tissue.

increased risk of developing Wilms’ tumors

THANK YOU

Duplex Collecting System

- The degree of duplication is variable

- duplication is complete when there are two separate collecting systems and two separate ureters , each with their own ureteral orifice ,

- duplication is incomplete when the ureters join and enter the bladder through a single ureteral orifice

Complete duplicated collecting system

Bilateral complete duplicated collecting system

Incomplete duplicated collecting system

THANK YOU

congenital renal anomalies

Health & Medicine