Page 622 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

606 PART 8 ■ Fundamentals of Hematological Analysis

Microscopic Exam ination

BOX 29.2 Wet Preparation Exam ination

Fresh synovial f uid should be examined under a clean cover-

Particulate Matter Found in Synovial Fluid slip by routine microscopy or cells and particulate material.

Cytoplasmic inclusions within granulocytes sparkle and can
Adipose tissue ragments appear to be light or dark. T ese inclusions are believed to

Amyloid brils represent distended phagosomes or droplets containing lipid.

Bacteria and ungi It is important to note whether crystalline material is intra-

Cartilage ragments cellular or extracellular. In acute attacks o gout and pseudo-

Cells gout, crystals are engul ed by leukocytes. During intercritical

Collagen brils periods, crystals may lie ree in the f uid. Immunof uorescent

Crystals studies have demonstrated that some inclusions contain

Fibrin strands and clumps immunoglobulins and complement.

Immune complexes Fracture or trauma to a joint can produce ree lipid drop-

Lipid lets in the synovial f uid, which can also be seen in aseptic

Metal and plastic ragments necrosis and at embolism. T ese droplets are rarely seen in

Parasites inf ammatory e usions. Irregular strands o brin or brillar

Rice bodies ragments o cartilage may be observed in specimens rom

Synovial ragments patients with degenerative arthritis.

Unrecognizable junk Cells and other particulate matter should not be con used

with crystalline materials. One basis or di erentiation is that

crystals have straight, parallel edges. In addition to routine light
he mucin clot procedure estimates the density and ri- microscopy, examination with a polarized light microscope is

ability o the precipitate that orms when synovial luid recommended or the identi cation o crystals ( able 29.15).

is placed in acetic acid. he addition o several drops o

normal synovial luid to a dilute (2% to 5%) acetic acid

solution results in the ormation o a tight, sticky, rope- Basic Calcium Phosphate

like mass (polymerization o synovial luid hyaluronate) Basic calcium phosphate (BCP) crystals include hydroxyapatite

that remains intact when shaken. A good or excellent clot (HA), octacalcium phosphate, and tricalcium phosphate. T e

implies high molecular weight hyaluronic acid and nor- size o BCP crystals is below the limits o resolution o optical

mal hyaluronate-protein interactions. A air or poor clot microscopy. I aggregated, they are visible by light micros-

implies in lammatory arthritis. here are, however, no copy and appear as shiny, laminated, printed coins. With a

standard criteria or per ormance o the test, and the end polarized microscope, BCP crystals are nonbire ringent.

point is subjective. BCP crystals are associated with subcutaneous calci ca-

tion and calci c periarthritis and tendinitis. In addition, BCP

crystals can be ound in both acute and chronic synovitis.

BOX 29.3

Monosodium Urate

Monosodium urate (MSU) crystals are 8 to 10 µm in length
Examples of Conditions Associated w ith and are needle or rod shaped. T e crystals may be pointed

Hemarthrosis
and intracellular or extracellular. With a polarization micro-

Anticoagulant therapy scope, MSU crystals appear as strongly bire ringent rods or

Hereditary de ciency o clotting actors (e.g., hemophilia needles that are bright against a dark, ully polarized back-

or von Willebrand’s disease) ground. With a red compensator, they appear yellow in color

In ection when the longitudinal crystal axis is parallel (negative bire-

Metallic joint prostheses ringence) to the slow component o the compensator. T e

Osteoarthritis crystals appear to be blue when perpendicular to the axis o

Postsurgery or prosthesis the compensator.

Preexisting arthritis MSU crystals are pathognomonic or gouty arthritis.

Pseudogout Calcium Pyrophosphate Dihydrate

Rheumatoid arthritis

Sickle cell disease (crisis) Calcium pyrophosphate dihydrate (CPPD) crystals are more eas-

Synovial hemangioma ily seen with a good light microscope. CPPD crystals assume

T rombocytopenia multiple, three-dimensional orms: rods, rhomboids, and

T rombocytosis parallelepipeds occur simultaneously.

rauma with or without racture With a polarizing microscope, CPPD crystals are less bire-
ringent than MSU crystals and are more di cult to identi y.