Urinary tract infections (UTI) are among the most common medical disorders in the world. Bacteria are the main infectious agent that causes UTIs, and bacteriuria and leukocyturia are the hallmarks of urinary sediment in patients with UTI. Bacteria…
Microscopic examination of the urinary sediment in the context of hyperbilirubinemia and increased urinary bilirubin excretion requires special attention to the unique chromatic characteristics acquired by the specimens. As serum bilirubin increases, a yellow-tinged urine becomes increasingly noticeable….
In the routine urinary sediment examination, you may come across 4 types of nucleated cells: 1. Squamous epithelial cells2. Leukocytes3. Transitional epithelial cells4. Tubular epithelial cells Let’s discuss how to differentiate between them. Squamous epithelial cells are easily…
Damage to the glomerular basement membrane allows plasma lipids to enter the urinary space. These lipids may appear in various forms, either as free lipid droplets, lipid casts, oval fat bodies, and/or as cholesterol crystals. In most cases,…
Several drugs, mainly antimicrobial or antiviral agents, can cause transient crystalluria, in isolation or in conjunction with other urinary abnormalities and a wide range of clinical implications. The factors favoring the formation of drug crystals are drug overdose,…
Urine acanthocytes are a distinct type of dysmorphic erythrocytes that can be found during microscopic examination of the urinary sediment. Their unique characteristics make them rather pathognomonic of hematuria that originates from a glomerular disease, i.e., glomerular hematuria…
Cystinuria is the most common kidney stone disease with Mendelian genetics. Caused by mutations in SLC7A9 and SLC3A1, affected patients excrete high amounts of cystine in their urine and are vexed by recurrent episodes of nephrolithiasis. Cystine stones…
This is a fictional case, designed for educational purposes The Case The patient is a 66 year-old with a history of hypertension who presented with complaints of fatigue and recurrent “sinus infections” over the past few months. He…
Eric Bywaters was the first to use the nomenclature “pigmented casts” in a 1941 British Medical Journal publication about crush syndrome where he illustrates pigmented casts (due to myoglobin) with a photomicrograph (Figure 1) of the kidney biopsy…
Hyaline casts are traditionally known to lack clinical significance. However, because they are frequently found during urinary sediment microscopy, hyaline casts should be correctly identified and distinguished from other types of casts. They are colorless transparent cylindrical structures…