Accurate measurement and documentation is
important in many aspects of dermatology
and dermatologic surgery. Lesional and
excisional dimensions are most often measured
rounded to the nearest millimeter and recorded for
proper insurance coding, clinical studies, and database
entries. Most often, measurements are made
with a millimeter ruler (ie, stainless steel or on a
marking pen), or from estimates based on accumulated
experience in the daily use of such measuring
devises. At times there is some difficulty in obtaining
precise measurements with such methods. There is a
risk of rounding errors, especially when relatively
broad lines made by a gentian violet skin-marking
pen surrounding the lesion or excision site are
incorporated in the measurement. These errors can
be compounded when measuring both lesional and
excisional dimension in cases where such measurements
are considered important such as in the
surgical treatment of primary cutaneous melanoma.