Crystalline-induced kidney disease: a case for urine microscopy

Urine microscopy is an integral part of the clinical evaluation of patients presenting with kidney disease [1, 2]. Along with history and physical examination, directed serum tests, dipstick urinalysis, and at times, renal imaging, urine sediment examination provides an informative view into the kidney. Identification and quantification of the cells, casts and crystals present in the spun urine sediment allow the clinician to synthesize all of the data and construct a rational diagnosis. This is particularly true for patients with crystalline-induced kidney disease [3]. We present illustrative cases of five different and clinically important causes of crystalline-induced kidney injury demonstrating the diagnostic utility of urine microscopy in clinching the diagnosis and facilitating therapy of the underlying process.