Unexpected crystalluria: Report of three cases

Abstract

Detection and reporting of crystals in urine is an integral part of a clinical laboratory. Presence of crystals is not always pathological and affected by a variety of pre analytical factors. Pathologically significant crystals are rare and seen in acidic urine. Here we report three such cases where urine crystals posed a reporting dilemma. Case 1: 3-year-old male child with nephrotic syndrome showed thorn apple shaped ammonium biurate crystals in urine with pH 6.8. Ammonium biurate crystals are seen in alkaline urine and this scenario of slightly acidic urine and background of nephrotic syndrome is a usual one. Case 2: 10-year-old male with fever, jaundice and hepatomegaly showed a urine pH of 5.6 and yellow round leucine crystals with radiating striations. Leucine crystals are indicative of severe liver damage and the child was found to have chronic Hepatitis B infection. Case 3: 35-year-old female with generalised weakness and prutitis, showed a urine pH of 6 and fine needle like clusters of bilirubin crystals. These crystals are rare and occur in background of severe hyperbiliribinemia, the patient was found to have a carcinoma involving head of pancreas. Morphology, solubility testing with organic/mineral acids and alkali aids in diagnosis under unexpected scenarios.