Purpose: The treatment of melanoma-in-situ and lentigo maligna melanoma has remained a difficult problem for clinicians around the world. The diffuse nature of these lesions and the unpredictability with which they progress from a melanoma in situ to an invasive melanoma are in large part the reasons for this difficulty. Techniques for surgical treatment have varied from wide local excision to Mohs surgery and staged excision procedures. Literature has suggested a 5mm marginal excision, yet this may lead to unacceptable rates of recurrence. Our purpose is to report the 10 year experience at one institution using staged excision for the treatment of melanoma in situ and lentigo maligna melanoma.
Methods: Staged excision was performed on 62 patients over a period from May 1997 to March 2008. Data on patient demographics, lesion characteristics and treatment was collected through an IRB approved chart review. Of the 62 charts reviewed 59 patients had a complete data set which could be used for analysis. Patient follow up was obtained through the use of the institutional cancer registry.
The staged excision procedure was performed over a three day period beginning with excision of the lesion with a 5-10mm margin at the first session. The patient and specimen were marked and the tissue was processed by pathology per our protocol as a rush overnight permanent section. Peripheral strips were processed en face while the central lesion was breadloafed in the standard pathology fashion. Positive margins were reported and the process was repeated with additional 5mm margins in areas found to be positive. Following lesion clearance immediate reconstruction was undertaken.
Results: Patient demographics were 100% Caucasian with 57.6% male and 42.4% female patients. The median age of the population was 70 years (range 40-89 years).
83.1% of patients presented with melanoma in situ with the remaining 16.9% presenting with biopsy diagnosed lentigo maligna melanoma. 22.0% of patients had undergone previous treatment with 15.3% having undergone excision, 8.5% cryotherapy and 1.7% immunotherapy. The most common lesion locations were cheek (47.5%), forehead/brow (18.6%) and nose (15.2%).
During the staged excision 62.7% of patients required a 10mm or greater excision to achieve clear margins. 50.9% of patients underwent 2 or more stages of excision. Median preoperative lesion size was 1.5cm (range 0.1-6.5) x 1.4cm (range 0.1-5.8). Median post operative lesion size was 3.1cm (range 1.4-10.9) x 3.4cm (range 1.1-8.7). Additionally 10.2% of patients were found to have an invasive melanoma after presenting initially with in-situ disease. Reconstruction was performed by a plastic surgeon in 81.3% of patients. Only 1 (1.7%) patient had a documented recurrence in a median 2.25 year follow up (range 0-10.17 years).
Conclusions: This study confirms that staged excision with immediate reconstruction is the treatment of choice for melanoma-in-situ. Our technique of excision and pathological evaluation has proven effective with a 1.7% recurrence rate. In addition 62.7% of patients required a 10mm excision or greater to achieve clear margin status. This would suggest that previous recommendations of 5mm margins for wide local excision should be readdressed.