AJKD Atlas of Renal Pathology: Nephrocalcinosis and Acute Phosphate Nephropathy

Renal calculi, commonly termed kidney stones, are crystalline solid masses that form in the kidneys but can occur at any point within the urinary system, encompassing the kidneys, ureters, bladder, and urethra.The pathophysiology of renal stones involves several key factors: supersaturation of the urine with stone-forming constituents, changes in urine pH, a decrease in urine volume, and the presence of substances that promote or inhibit stone formation.Supersaturation of Urine: This is the...

The kidneys are intricate organs with millions of working units known as nephrons. Each nephron features two major structures: the renal corpuscle, which facilitates blood plasma filtration, and the renal tubule, which handles the glomerular filtrate. Blood supply is directly linked to the nephrons. The renal corpuscle consists of the glomerulus, a capillary network, and the Bowman's capsule, a double-walled epithelial structure that encases the glomerulus. The filtering of blood plasma...

Renal calculi, or kidney stones, are solid deposits of minerals and salts formed inside the kidneys. In medical terminology, "calculus" refers to the stone itself, while "lithiasis" describes the process of stone formation. Depending on their location within the urinary system, these stones may be classified as either urolithiasis, when situated within the urinary tract, or nephrolithiasis, when located within the kidneys. Each term signifies the specific impact of the stone.Predisposition...

Acute kidney injury (AKI) causes are categorized into three primary categories based on the location of the injury: prerenal, intrarenal (or intrinsic), and postrenal causes. This classification guides clinical management and illustrates how different pathways can impair kidney function.Etiology and Pathophysiology of Acute Kidney Injury1. Prerenal causesEtiology: Prerenal Acute Kidney Injury, the most common type, occurs when reduced blood flow to the kidneys decreases filtration capacity...

The renal tubule is divided into three parts: the proximal convoluted tubule (PCT), the Loop of Henle (LOH), and the distal convoluted tubule (DCT).
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...

The diagnosis of renal calculi involves several imaging techniques, including non-contrast CT scans and ultrasound. These methods help visualize kidney stones, assess their size and location, and detect possible obstructions. Additionally, Measuring urine pH is useful for diagnosing specific stone types, such as struvite (alkaline pH) and uric acid stones (acidic pH). Cystine stones are primarily linked to cystinuria, a genetic condition. A urinalysis helps detect blood in the urine (hematuria)...