SURGEON should report size
Actually, the correct way to document size of lesion is for the provider who will be excising the lesion to report the PRE-EXCISION measurement of the lesion, plus MINIMUM margin required for complete excision. The reason for this is that the tissue will shrink once excised, so the size reported by the pathologist is smaller than the size before excision. If your physician isn't reporting the size, but relying on pathology, s/he is leaving money on the table.
Also, if the resulting surgical wound requires layered or complex closure, the length of the incision should also be reported (this may very likely be LONGER than the diameter of the lesion itself).
Hope that helps.
F Tessa Bartels, CPC, CEMC