A 65 year old man presents to your office complaining of severe pain and swelling in his left knee. He's had these symptoms 2-3 times in the past but they resolved without medical attention. On exam, you notice a red, hot, swollen left knee. Here's a radiograph:
You tap the knee. The synovial fluid has 20,000 leukocytes, 90% neutrophils. You examine it under compensated polarized microscopy:
Challenge: What do you think?First image shown under GNU Free Documentation License; second image shown under Fair Use.
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2 comments:
Sudo I
This is pseudogout or calcium pyrophosphate crystal deposition (CPPD) disease. The plain film shows evidence of calcium crystal deposition or chondrocalcinosis; this appears as punctate and linear radiodensities in fibrocartilage and hyaline or articular cartilage. CPPD is also associated with degenerative changes in joints. The synovial fluid is most diagnostic with positively birefringent CPPD crystals, often phagocytosed within polymorphonuclear leukocytes.
Sources: UpToDate; Wikipedia; original picture by Ralph Schumacher.
Too easy?
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