Based on recessional velocity of 10805 km/sec, about 480 million light years away. Given that and apparent size of 0.95 by 0.1 arcmin, about 130 thousand light years across. Note: Entering PGC 91591 in the Wikisky database shows PGC 1591 (this is a common truncation error for Wikisky entries). Use the coordinates (or FGC 2126) as the search string to see the correct galaxy.