Autosomal Recessive Polycystic Kidney

Autosomal recessive polycystic kidney (PCK; Potter type I) is an autosomal recessive disorder, previously termed infantile PCK, characterized by bilateral microcystic change of renal tubules leading to enlarged non-functional kidneys with maintenance of their reniform shape. Most cases manifest in utero but some may be evident after birth or childhood. PCK may be associated with abnormality of fibrocystin, a receptor protein that acts in collecting-duct and biliary differentiation.

          Fig 1

Incidence: 1 in 40,000-50,000 births, male/female, 1:1.

Sonographic findings:

  • Bilateral enlarged (above the 90th percentile for length and width), echogenic kidneys with reniform shape. Fig 2, Fig 3, Fig 4, Fig 5
  • Oligohydramnios with non-visualization of the bladder, usually not before 15 weeks.
  • Pulmonary hypoplasia.
  • Usually diagnosed after 18 weeks.

Fig 1:  Schematic drawing of polycystic kidney (enlarged reniform shape)

Fig 2:  Polycystic kidneys   Coronal scan of the abdomen: symmetrical markedly enlarged echogenic kidneys (* = renal pelvis)

Fig 3:  Polycystic kidneys   Cross-sectional scan of the abdomen: symmetrical markedly enlarged echogenic kidneys (* = renal pelvis, arrowhead = spine)

Fig 4:  Polycystic kidneys  Coronal scan of the abdomen: symmetrical markedly enlarged echogenic kidneys

Fig 5:  Polycystic kidneys   Oblique coronal scan of the abdomen: symmetrical enlarged echogenic kidneys containing numerous microcystic lesions (* = renal pelvis)

Video clips of multicystic dysplastic kidney (MCDK)

Polycystic kidney:  Bilateral enlarged echogenic kidneys with pyelectasis

Polycystic kidney:  Bilateral enlarged echogenic kidneys with severe oligohydramnios

Associations: Hepatic fibrosis, Meckel Gruber syndrome, trisomy 13.

Management: Termination of pregnancy can be offered. Vaginal delivery without electronic fetal monitoring in labor is appropriate.

Prognosis: Very poor, particularly the cases with severe oligohydramnios and fetal kidneys >4 SD.

Recurrence risk: About 25%.