Bilateral enlarged kidneys replaced by cysts: diagnose by age-specific cyst counts, measure total kidney volume (it predicts progression and qualifies for therapy), and look for complications — haemorrhage, infection, stones, and liver cysts.
Orient first
- Diagnostic ultrasound criteria depend on age and family history (unified criteria — verify).
- Height-adjusted total kidney volume (htTKV) on MRI stratifies risk (Mayo imaging classification — verify).
- Extrarenal: liver cysts, intracranial aneurysms (screening by family history), pancreatic cysts.
Acquire the study
- Curvilinear probe; both kidneys in longitudinal and transverse planes.
The manoeuvre
- Count cysts per kidney and compare with the age-specific criteria.
- Kidney length in cm on both sides.
- Complicated cysts: internal echoes, fluid–debris levels.
- Liver cysts.
What confirms it
- Bilateral cysts meeting the age-specific criteria with family history or genetics.
What licenses you to exclude it
- Age-specific criteria allow exclusion in an at-risk adult when the cyst count is below threshold (verify).
The classic misread
- Diagnosing ADPKD from a few simple cysts in an older adult — simple cysts increase with age.