Page 623 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

CHAPTER 29 ■ Body Fluid Analysis 607

TABLE 29.15 Characteristics of Synovial Fluid Crystals

Crystal Microscopic Appearance With Polarization Associated Disorders

Monosodium urate (MSU) Acicular Strongly negatively birefringent Acute gouty arthritis

Red compensator in a polariz- Tophaceous gout

ing microscope—yellow color

Calcium pyrophosphate Polymorphic Weakly positively birefringent CPPD deposition disease

dihydrate (CPPD) Red compensator in a polar-

izing microscope—blue color

Calcium hydroxyapatite Too small to identify; with Not birefringent Calci c tendinitis

electron microscopy, as small Apatite-associated destruc-

needles or rods tive arthritis

Soft tissue calci cations

in the connective tissue

diseases

Calcium oxalate Polymorphic, classically Variable; positively birefrin- Chronic renal disease,

bipyramidal gent or strongly to weakly oxalosis

birefringent

Lipid liquid “Maltese cross” Strongly positively Acute and chronic arthritis

birefringent

Cholesterol Large, plate-like, with Strongly variably birefringent Chronic rheumatoid effusions

punched-out corners

Corticosteroids Polymorphic clumps, rods, Strongly variably birefringent Iatrogenic

or rhomboids

Talc Varying size Strongly positively Contaminant

birefringent

MSU, monosodium urate; CPPD, calcium pyrophosphate dihydrate.