Disorders of the Kidneys
This chapter gathers the structural and cystic disorders of the kidney — the congenital anomalies, the cystic diseases (simple cysts through polycystic kidney disease), and how to tell a harmless cyst from one that might be cancer.
The big picture
This chapter gathers the structural and cystic disorders of the kidney — the congenital anomalies (which build on the embryology lesson), the cystic diseases (simple cysts through polycystic kidney disease), and how to tell a harmless cyst from one that might be cancer. The practical thread is distinguishing benign from worrying — a simple cyst needs nothing, a complex one needs scrutiny, and polycystic disease needs lifelong management.
The framework: congenital anomalies (recap), simple vs complex cysts (the Bosniak classification), and autosomal dominant polycystic kidney disease (ADPKD).
Mechanism pathway
Tap any step to see why it happens.
Diagnostic algorithm
Each step answers one question. Tap to expand.
Board traps
Bosniak grades cyst malignancy risk: I–II benign, III indeterminate (operate), IV malignant.
A "simple cyst" must genuinely be simple — complex features change everything.
ADPKD is autosomal dominant, ~95% bilateral, with hypertension, hepatic cysts, and berry aneurysms.
Horseshoe kidney sits low (under the IMA) and has two collecting systems — higher stone/obstruction risk.
CT is the most accurate modality for renal abscess.