Relation between size of skin excision, wound, and specimen.

BACKGROUND

Skin wounds differ in shape and size compared with the planned excision, and skin shrinks after excision and fixation.

OBJECTIVE

This study was designed to quantify and to analyze the differences between the size and shape of the planned excision, wound, and specimen.

METHODS

Eighty-six patients with 93 benign or malignant skin tumors were prospectively studied. Length and width measurements were made of the lesion, planned surgical excision, postexcision wound, and prefixation and postfixation specimens. The results were analyzed to identify the effects of patient age and sex, and lesion type and site.

RESULTS

Wound size was larger than planned excision size in 90% of wounds, and this effect was greatest in young patients and at trunk and limb sites. Excision and fixation caused the specimens to shrink so that the postfixation area was on average 48% of the planned excision area; benign tumors shrank more than malignant tumors.

CONCLUSION

Significant differences among planned excision, wound, and specimen sizes are influenced by patient age and by lesion site and type. These results demonstrate that wound size is not equivalent to tumor size, a conclusion often made in Mohs surgery. Furthermore, assessment of tumor clearance margins from fixed tissue does not reflect in vivo clearance margins.