CAP Pro Course - Urinalysis - Microscopic Urinalysis Part 2 - Crystals and Casts (2025 & 2026)

Author: Marjorie Di Lorenzo, MLS(ASCP)SH
Reviewers: Joshua J. Cannon, MS, MLS(ASCP)CMSHCM and Laurie Bjerklie, M.A., MLS(ASCP)CM

Continuing Education Credits

Objectives

  • Identify normal and abnormal urinary crystals and correlate abnormal crystals with clinical conditions.
  • Identify urinary casts and correlate with clinical diseases and conditions.
  • Discuss methods to reduce cast identification errors.

Course Outline

  • Identify normal and abnormal urinary crystals and correlate abnormal crystals with clinical conditions.
      • Crystal Formation and Identification
      • Normal Urine Crystals
      • Abnormal Urine Crystals
      • Additional Test Methods for Crystal Identification
      • A routine urinalysis was ordered on a 30-year-old man during his yearly wellness visit. The patient collected a random urine sample. The sample was de...
      • After a hard day of snow skiing, a 28-year-old white male patient complained of lower back pain. This was attributed to the exertion of snow skiing th...
      • A 14-year-old female patient was found lying on the bathroom floor early one morning, doubled over with severe lower back and abdominal pain. She was ...
      • An infant girl was born one month premature. Two days after she was released from the hospital, she developed jaundice. Daily bilirubin tests indicate...
      • The crystals shown on the right were observed in urine that had been refrigerated. The macroscopic chemical analysis of the urine had a positive resul...
      • Bilirubin crystals are abnormal crystals that may be associated with liver disease. Which of the crystals listed below are also abnormal crystals that...
      • These crystals were observed under polarized light. What is the identity of these crystals?
      • You are performing a microscopic analysis on a sediment that contains frequent fatty casts. You also observe these crystals. What are these crystals?
      • What is the identity of these crystals, observed in the sediment of a urine with a pH of 6.5?
  • Identify urinary casts and correlate with clinical diseases and conditions.
      • Identification of Casts
      • Casts and Clinical Significance
      • Table 4. Characteristics and Clinical Significance of Casts
      • A medical laboratory scientist has observed this structure while examining urine sediment under high power (400X magnification). What is the most like...
      • Which of the following microscopic urine constituents helps to differentiate a case of cystitis versus pyelonephritis?
      • From the choices below, indicate what the observation of broad casts in urine sediment represents.
      • Which of the following elements is not associated with the presence of red blood cell (RBC) casts in the urine?
      • A 27-year-old woman presented in her physician’s office with fever, painful urination, and abdominal pain. Her physician ordered a clean catch m...
      • A 2-year-old male patient presented in the emergency department with severe edema in the face, legs, and feet. Complete blood workup and a routine uri...
      • A routine urinalysis was ordered on a 92-year-old male patient diagnosed with stage 4 kidney disease with symptoms of chronic renal failure. The cast ...
      • A 55-year-old woman was taken to the emergency department after collapsing while running a marathon. Blood work and a routine urinalysis were ordered ...
      • This cast was observed during the microscopic examination of urine sediment. The patient was being seen for a routine physical. What is the identifica...
  • Discuss methods to reduce cast identification errors.
      • Correlation of Casts with Other Urinalysis Results
      • Microscopic Errors in Identification of Casts
      • A 14-year-old male patient presents to his physician with abdominal pain, edema, headaches, and weakness. He also reports voiding dark-colored urine. ...
      • A newly-graduated medical laboratory scientist (MLS) reported many hyaline casts seen in the urine sediment of a 20-year-old female patient. The urina...
      • This structure was incorrectly identified as a hyaline cast by the laboratorian. What is the correct identification?
      • Which finding on a urine reagent strip test would help to confirm the identity of this cast?
      • What characteristic would distinguish a white blood cell (WBC) cast from a clump of WBCs?
      • Which of the following elements are helpful in the differentiation of casts versus fibers in the urine sediment?
      • The urinalysis results from an 8-month-old girl were as follows:TestResultReference ValueColorYellowYellowClarityHazyClearGlucoseNegativeNegativeProte...
      • A urinalysis is ordered on a patient with nephrotic syndrome. The medical laboratory scientist performing the test notes a few casts on the microscopi...
      • The structure indicated by the arrow on the right was observed during a microscopic examination of urine sediment. How should this structure be classi...
  • References
      • References

Additional Information

Level of Instruction: Intermediate
Intended Audience: This program is designed as an educational and training tool for MLS, MT, and MLT personnel, medical laboratory science students and interns, pathology residents, and practicing pathologists.
Author Information: Marjorie Di Lorenzo, MLS(ASCP)SH, is a medical technologist with 40 years of laboratory experience. She has assumed many roles in her career, first as a staff technologist and moving into roles of laboratory management and education in CLS and MLT programs. She is the co-author for several textbooks and articles on the topics of urinalysis and body fluids. Marjorie is currently the Phlebotomy Technician Program Coordinator at Nebraska Methodist College and an Adjunct Instructor in the Division of Laboratory Sciences at the University of Nebraska Medical Center, Omaha, Nebraska.
Reviewer Information:
Joshua J. Cannon, MS, MLS(ASCP)CMSHCM received his Bachelor of Science and Master of Science in Medical Laboratory Science from Thomas Jefferson University in Philadelphia, PA. He holds Medical Laboratory Scientist and Specialist in Hematology certifications through the ASCP Board of Certification. He was a professor at Thomas Jefferson University for seven years before transitioning into his current role as an Education Developer. His areas of expertise and professional passions include clinical hematology and interprofessional education.
Laurie Bjerklie, M.A., MLS(ASCP)CM, is currently an Education Developer. She earned a B.S. in Medical Laboratory Science from the University of North Dakota and an M.A. in Curriculum and Instruction from Saint Xavier University. She has over 15 years of experience in higher education and has held program director and faculty positions in both MLT and MLS programs.

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