Margin involvement after the excision of melanoma in situ: the need for complete en face examination of the surgical margins.
BACKGROUND
The standard treatment for cutaneous melanoma in situ is surgical excision followed by standard pathologic evaluation. Serial cross-sectioning (bread-loafing) may result in false negative margin examination and higher local recurrence rates than Mohs micrographic surgery, which histologically evaluates the entire surgical margin.


OBJECTIVE
To estimate the sensitivity of bread-loafing in detecting residual melanoma in situ at surgical margins.


METHODS
A retrospective study was performed including 36 cases of melanoma in situ treated with Mohs surgery with positive margins after initial excision with 5 mm margins. The length of the margin involved with melanoma was measured. The ability of bread-loafing to detect residual tumor was calculated.


RESULTS
The average linear extent of tumor at the surgical margin was 1.4 mm. Bread-loafing at 1, 2, 4, and 10 mm intervals would have a 58, 37, 19, and 7% chance of detecting positive margins, respectively. In order to detect 100% of positive margins, bread-loafing would have to be performed every 0.1 mm.


CONCLUSIONS
Bread-loaf cross-sections through excised melanoma specimens are inherently unreliable for detecting residual melanoma at the surgical margins. We recommend complete histologic margin control of the entire surgical margin using en-face tissue orientation (Mohs technique) to reduce the risk of recurrence.
Kimyai-Asadi
Arash
A
DermSurgery Associates, Houston, Texas 77030, USA. akimyai@yahoo.com
Katz
Tracy
T
Goldberg
Leonard H
LH
Ayala
Gabriel B
GB
Wang
Steven Q
SQ
Vujevich
Justin J
JJ
Jih
Ming H
MH
D002278:Carcinoma in Situ / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008545:Melanoma / Q000473:pathology* / Q000601:surgery; D015580:Mohs Surgery; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D018365:Neoplasm, Residual / Q000473:pathology* / Q000601:surgery; D012086:Reoperation; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery