A tumor is classified as benign when it's unlikely to spread & as this when it's cancerous
Sometimes anal cancers extend from one area into the other, so it's hard ... 
Leiomyomas: Benign tumors that develop from smooth muscle cells ... advanced 
type of AIN, which is considered a pre-cancer but not a true ..... these nodes don't 
contain cancer cells, it is very unlikely the cancer would have spread.