Polycystic Kidney Disease – Top USMLE Diseases

Polycystic kidney disease (PKD) is an inherited genetic disorder leading to the development of numerous fluid-filled cysts in the kidneys. The 2 main types of PKD are autosomal dominant polycystic kidney disease (ADPKD), which is often diagnosed in adulthood, and autosomal recessive polycystic kidney disease (ARPKD), which is often diagnosed antenatally or shortly after birth. ADPKD patients commonly present with hypertension, hematuria, and flank pain. Extrarenal manifestations include intracerebral aneurysm, hepatic and pancreatic cysts, and cardiac valvular abnormalities. Diagnosis is by history, physical exam, and ultrasonography. Management requires a multidisciplinary approach and many patients require renal replacement therapy. The end goal is to slow the progression of renal disease by controlling hypertension, proteinuria, and symptoms. ADPKD prognosis is dependent on a variety of factors. A cerebral aneurysm is a complication associated with a particularly poor prognosis.

A kidney cyst can arise in any part of the nephron and collecting ducts, and can be found incidentally on imaging tests, or can be part of a renal or systemic disease. Renal cystic diseases consist of a large spectrum of diseases that differ in regards to pathophysiology, prognosis and treatment and that can be usefully divided into hereditary, acquired and developmental conditions. Hereditary renal cystic diseases often lead to kidney failure and are commonly associated with extrarenal manifestations, whereas non-genetic cystic disorders are usually limited to the kidney and rarely result in kidney functional deterioration.