Toronto probably isn't that polarized by income to begin with. The pattern is probably mix of wedge and doughnut, maybe closer to wedge, if you look at the "Tale of Three Cities" maps:
http://www.urbancentre.utoronto.ca/pdfs/curp/tnrn/Three-Cities-Within-Toronto-2010-Final.pdf
The wealthiest areas are along the subway lines, and the poorest are near the border (far from subway, lack of fare integration with 905 transit). The article is only for Toronto proper but Malton probably would be in City #3 as well. Physical and political isolation seems the common theme.