Best Post of April 2013: A Rich Focus

The next in our "Best of the Month" series is a post from April 16, 2013.

The grey arrow is pointing to a Rich focus that has hemorrhaged into the subarachoid space

A Rich focus is a tuberculoma in the cerebral cortex. Rich foci become particularly significant when they rupture into the subarachnoid space and cause tuberculous meningitis. This entity is named for Johns Hopkins pathologist Dr. Arnold Rice Rich (1893-1968), who first described it.