Urine Microscopy

+Dr. Mohammed Iqbal Musani, MD

Urine Microscopy :

• Cells Casts CrystalsCells Casts Crystals.

• Casts are formed within nephron.

• Casts Suggest Kidney pathology.

• Casts can be made up of Protein, lipid, cells or mixed.

• Crystals suggest high concentration or altered solubility.

WBC in Urine :

White blood cell cast

• Seen in interstitial disease most commonly

• Also seen in glomerulonephritis

WBC Cast Urine:

Mixed Cast Urine:

Waxy cast

• Thought to result from the degeneration of cellular casts

Non-renal epithelial cells

• Uro-epithelium is columnar– If there are a lot of these it

means there is sloughing of the system

• Skin is squamous– If there are a lot of

squamous it is a contaminated specimen

Urine Oxalate Crystals:

White blood cells/red blood cells in urine

                                                               

                         

This is a photograph of urinary sediment under brightfield microscopy (250X magnification). The sediment contains two red blood cells (right) and one white blood cell (left). The white blood cell appears to have a lobulated nucleus.

Red blood cells in urine

                                                                 

                

These are red blood cells found in urinary sediment under bright field microscopy (160x magnification).

White blood cells and bacteria

                                                                                  

These are white blood cells and bacteria found in urinary sediment using interference-contrast microscopy. The cell in the center has a pseudopod extending from its cytoplasm indicating amoeboid motion.

Squamous epithelial cells

                                                                                

Shown here is a group of squamous epithelial cells in urine sediment. Interference-contrast microscopy was used to enhance surface characteristics of the cells (200X magnification). A few white blood cells and bacteria are visible in the periphery.

Squamous epithelial cell in urine

                                                                

                       

This is a squamous epithelial cell under brightfield microscopy (250X magnification).Squamous epithelial cells are characterized by a small, round, central nucleus with a large amount of granular or wrinkled cytoplasm (a "fried egg" appearance).

Renal Epithelial Cells

                                                                 

              

A group of attached renal tubular epithelial cells are seen in the center of this slide. The background contains white blood cells and red blood cells (bright field microscopy, 250X magnification)

Bacteria and white blood cells

                                                                 

                  

This is a low power view (100X magnification) of urine with bacteria and several leukocytes in the field. Bacteria are bacillary and diffusely scattered throughout. The urine is stained with Sternheimer-Malbin stain.

Mucus

                                                                                          

This slide shows mucus in urine with two entrapped white cells. There are also two red cells present, one within the mucus and one above it. Mucus fibers are fibrillar and delicate. They have a very low refractive index. (Bright field microscopy, 160X magnification.)

Budding yeast cells

                                                                                           

Budding yeast are visible on the left side of this slide with a squamous epithelial cell on the right. There are no segmented neutrophils seen. This suggests the yeast are a contaminant and not causing a urinary tract infection (bright field microscopy, 200X).

Hyaline cast

                                                                 

              

Hyaline casts are difficult to see due to their low refractive index. This one is granular, which makes it easier to visualize. (Bright field microscopy, 200X magnification.)

Red blood cell cast

                                                                 

              

This slide shows a red blood cell cast with red blood cells concentrated at one end.(Bright field microscopy, 160X magnification)

White blood cell cast

                                                                 

            

This is a white blood cell cast with intact leukocytes. The leukocytes have multilobed nuclei. (Bright field microscopy)

Coarsely granular cast

                                                                 

              

This coarsely granular cast is easily seen with interference-contrast microscopy at 160X magnification.

Waxy cast

                                                                 

              

This is a waxy cast seen in urine with interference-contrast microscopy at 160X magnification. The cast is surrounded by red blood cells and segmented neutrophils.

Waxy cast

                                                                 

              

This is a waxy cast seen in urine with interference-contrast microscopy at 160X magnification. The cast is surrounded by red blood cells and segmented neutrophils.

Amorphous urates in urine

                                                                 

          

Amorphous urates appear as fine pink or brownish-tan granules (brightfield microscopy, 200X magnification). They are salts of uric acid and are normally found in acid or neutral urine.

Uric acid crystals in urine

                                                                  

         

Uric acid crystals exhibit extreme pleomorphism in size and in shape. They appear readily in acid urine allowed to stand at room temperature. (Bright field microscopy, 160X magnification)

Calcium oxalate crystals in urine

                                                                 

          

Calcium oxalate crystals are usually found in acid urine. They commonly appear octahedral.(Brightfield microscopy, 100X magnification.)

Amorphous phosphates in urine

                                                                           

Amorphous phosphates appear in neutral to alkaline urine as fine, colorless or slightly brown granules. White precipitate is observed on centrifugation. (Brightfield microscopy, 160X magnification.)

Triple phosphate crystals in urine

                                                                 

         

Triple phosphate crystals, viewed here with interference-contrast microscopy (160X magnification), resemble prisms or "coffin lids". They are found normally in alkaline or neutral urine. They are colorless.

Ammonium biurate crystals in urine

                                                                 

          

Ammonium urate crystals are easily distinguished by their golden brown color and "thorn apple" shape. They are seen here under bright field microscopy (160X magnification). They are the only urate crystals that appear in alkaline urine.

Calcium phosphate crystals in urine

                                                                 

          

Calcium phosphate crystals assume various forms including the rosette and pointed finger forms shown here with bright field microscopy (160X magnification). They appear most often in alkaline urine.

Calcium carbonate crystals in urine

                                                                 

          

Calcium carbonate crystals are small and colorless and appear in alkaline urine as granules or as small dumbbells. Bacteria are also present in this field (brightfield microscopy, 250X magnification).

Cystine crystals in urine

                                                                 

          

Cystine, an amino acid, is an abnormal finding in urine. Rarely seen, these crystals are found in acid urine and are seen as thin, colorless, hexagonal plates. (Brightfield microscopy, 160X magnification.)

Tyrosine crystals in urine

                                                                           

Tyrosine crystals are not normally found in urine. They are products of protein metabolism and appear in urine of people with tissue degeneration or necrosis (acute liver disease, severe leukemia, typhoid fever, and smallpox). They are present only when urine is acid. They are colorless to yellowish brown, needle shaped crystals and have a fine silky appearance. The needles may be single or arranged in sheaves or rosettes. Tyrosine crystals usually appear in urinary sediment together with leucine crystals

Leucine crystals in urine

                                                                           

Leucine crystals are not normally found in urine They appear in urine in association with tyrosine and are manifestations of the same clinical conditions. When found, leucine crystals are in acid urine in the form of spheroids with concentric striations. They are dense, highly refractive and appear as yellowish brown bodies. (Brightfield, 160X magnification)

Cholesterol crystals in urine

                                                                           

Cholesterol crystals are seen in the center of this field with squamous epithelial cells on either side. Cholesterol crystals are found in acid or neutral urine. They appear as regular or irregular transparent plates. They may occur singly or in large numbers. Usually one or more corners are cut off or notched, justifying their description as "stair step crystals". They are not commonly seen and are always considered pathological. They can be found in various renal diseases. (Brightfield microscopy, 160X magnification.)

Sulfa crystals in urine

                                                                           

Sulfonamide crystals form primarily in acid urine. The shape and color of these crystals are extremely variable, depending on the particular sulfonamide being administered to the patient. The most common forms encountered include rosettes, fan shapes and those resembling shocks of wheat. Sulfa crystals have pathologic significance, since they tend to form renal calculi that may damage renal tubules. (Brightfield microscopy, 160X magnification.)

Fecal material in urine

                                                                           

Fecal material can usually be identified by its brown coloration, and the assortment of bizarre shapes and sizes of component elements. Fecal contamination of urine most often occurs in incontinent babies or elderly persons. (Brightfield microscopy, 40X magnification)

Talc in urine

                                                                          

Talcum powder, commonly used as a dusting powder to prevent chafing or heat rash, appears as a contaminant in urine as crystals. (Brightfield microscopy, 128X magnification.)

Starch in urine

                                                                           

A derivative of cornstarch is used as a dusting powder for surgical gloves. It can enter the urine during catheterization. The starch granules are usually identifiable by their size, shape and high refractive index. (Brightfield microscopy, 100X magnification.)

Cotton fiber in urine

                                                                          

A cotton fiber is easily identified by its size. A cotton fiber is seen here with squamous epithelial cells and white blood cells.(Brightfield microscopy, 51X magnification.)

Fiber in urine

                                                                           

This slide depicts a fiber artifact found in urine under brightfield microscopy at 200X magnification.

So…what is a cast???

• Protein based cylindrical molds of the renal tubule

• Form in distal tubules and collecting ducts

• Result of damage to the renal tubule

• Can contain cells and other material

• Dehydration and acidic urine especially predisposes to cast formation

Formation of Casts:

Red cell cast

• Almost always associated with glomerulonephritis or vasculitis

• Virtually exclude extra-renal causes of bleeding

Red cell Casts in Urine:

Epithelial Casts in Urine:

Granular Casts in Urine:

Granular cast

• Non-specific but usually pathologic

• Usually the ‘granules’ are from the degeneration of cellular casts

White blood cell cast

• Seen in interstitial disease most commonly

• Also seen in glomerulonephritis

WBC Cast Urine:

Mixed Cast Urine:

Waxy cast

• Thought to result from the degeneration of cellular casts

Non-renal epithelial cells

• Uro-epithelium is columnar– If there are a lot of these it

means there is sloughing of the system

• Skin is squamous– If there are a lot of

squamous it is a contaminated specimen