Lab Case 79

A 72 year old man prsents with a swollen, hot and painful knee. You aspirate the effusion and find the following:

Volume: 22ml

Description: turbid yellow

Leucocytes: 14300 /uL

PMN  95%

Mononuclear: 5%

RBC: 3100 /uL

No bacteria seen

Crystals: Ca pyrophosphate dihydrate


  1. What is our diffrential diagnosis prior to the results?
  2. What is the diagnosis?
  3. What is the utility of leucocytes in synovial fluid?
  4. Compare the features of Gout and pseudogout