Friday, July 27, 2012

Image Quiz

Answer
The image shows Maltese crosses. These Maltese crosses appear to reside mostly within oval fat bodies (OFBs). OFBs are cells with birefringent fat droplets within their cytoplasm. Under low power magnification, oval fat bodies are often seen as large brown spots (sometimes almost black). This coloration is due to the yellowish brown pigmented fat making the droplets. These cells are usually seen in a context of heavy proteinuria. True oval fat bodies show a typical "maltese cross" interference pattern when viewed under polarized light. This interference is a crystalline structure property, and is due to the presence of esterified cholesterol in a liquid crystal state. Naturally, cholesterol-free droplets are not birefringent.

Question
This is a urine evaluated under polarized light. What does the image show?