"Lugan" is likely bastardized speak in America for someone with Lithuanian heritage. I grew up on the South Side of Chicago, where all my relatives came from the Marquette Park (aka Lithuanian Plaza) area -- it's the biggest population of Lithuanians in the world outside of Vilnius.
It's also where the Blues Brothers run over the Nazi march demonstrators in their 1980 movie... as the Nazis did, in fact, lobby to march through Marquette Park in the 60's & 70's:
http://www.marquettepark.net/martin...icannazipartyskokieatmarquetteparkdotnet.html
And where I grew up, "Lugan" was used as a term much like "nigga" might be used in the black community: cool to use among your own kind, but it is also a reason to kick the shit out of another person if they used it and they weren't of Lithuanian descent.
My guess is that it's a Lithuanian immigrant thing. At least in Chicago.