Anything over 4 cm is technically "increased procedural service" so a -22 modifier could be used.
An appropriate use of the -22 modifier is when a procedure is truly more complicated that the standard one, although it is not necessarily harder in the usual sense. In this instance, one is probably performing two procedures, rather than one. An example would be the laparoscopic "take down" of a prior hiatal hernia repair (and there is no such code for this) and the performing of a new, different type of hernia repair. There obviously is more work involved in this "double surgery."
My office has interpreted that any lesion removal over 8 cm warrants the addition of the -22 modifier and we have been instructed to code it as such. Your interpretation may vary.