Best Post of August 2011: Benignity in meningioma indicated by smiley face nucleus

The next in our "Best of Month" series is from August 16, 2011:

Drs. John Donahue and Ed Stopa sent in the photomicrograph below from an article they published in 1999 describing a benign meningioma. They conclude: "In this case, another factor in favor of the tumor being benign is that its nuclei are smiling (arrow)."