Calcium
Pyrophosphate Crystal Deposition
Disease (CPPD)
(Pseudogout)
(Chondrocalcinosis)
Epidemiology:
- >50y, more
common with increasing age
Common sites:
- menisci / knees
- wrists
- elbows
- shoulders
- ankles
- intervertebral discs
Gross features:
- Deposits first
develop in articular matrix, menisci, and intervetrebral discs
- Chalky white
friable deposits
- Mass-like
aggregates like tophi rarely
Histologic features:
- Neutrophil-rich inflammatory infiltrate
- Deposits are oval,
blue-purple aggregates
- Foreign-body
giant cell reaction surrounding them
- Crystals are weakly birefringent
and form geometric shapes
- Best seen on deparafinized, unstained slides
Immunophenotype:
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Marker:
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Sensitivity:
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Specificity:
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Molecular features:
- ANKH gene mutation
in AD familial form
- Transmembrane inorganic pyrophosphate transport
channel
Other features:
- Secondary:
- Previous joint
damage
- Hyperparathyroidism
- Hemochromatosis
- Hypomagnesemia
- Hypothyroidism
- Ochronosis
- diabetes
References: