Abstract
Melanoma-in-situ (MIS) represents 45% of all melanomas. The margins of MIS are often poorly defined with extensive subclinical disease. Standard fusiform excision with 5-mm margins results in positive margins in up to a third of cases. To decrease the incidence of involved margins, we use a staged excision approach for MIS. First, patients undergo excision under local anesthesia of a 2- to 3-mm “contoured” rim of tissue optimally 5 mm beyond the visible extent of the lesion. Formalin-fixed paraffin-embedded en face sections from this excision are then evaluated, if necessary with the aid of immunohistochemical stains. Any positive margins are further excised. When all margins are negative, the central area is then excised and reconstructed. A total of 61 patients with MIS or lentigo maligna melanoma underwent staged contoured excisions from 2004 to 2007 at Moffitt Cancer Center. We analyzed data only from patients with MIS of the head and neck. Patients with known invasive melanoma or non–head and neck primary disease were excluded. Demographics, tumor characteristics, margin status, number of stages, and type of reconstruction and recurrences were evaluated. Forty-nine patients with MIS of the head and neck, 28 (57%) male and 21 (43%) female, 42 to 88-years-old (median 72; mean 70), underwent staged contoured margin excision before definitive central tumor excision and reconstruction. The final surgical defect size ranged from 2 to 130 cm2 (median 16 cm2). Twelve patients (24%) required reexcision of at least one margin; the median number of reexcisions was 1 (range 1–2). There seemed to be a positive association between lesion size and margin status (as well as number of excisions needed to clear the margin). Unsuspected invasive melanoma was found in the central specimen in six patients (12%). Even small tumors could have unsuspected invasive melanoma: invasive cancer was seen in 4 (21%) of 19 tumors ≤2 cm in greatest dimension and 2 (7%) of 30 > 2 cm, respectively. Surgical defects were reconstructed with flaps in 18 (37%), full-thickness grafts in 20 (41%), and split-thickness grafts in 10 patients (20%). Median time from first margin excision to completion/final reconstruction was 7 days (range 7–63 days). No local recurrences have been reported at a median follow-up of 14 months (range 1–36 months). This technique allows for careful margin analysis and subsequent central tumor excision with simultaneous reconstruction. This approach minimizes the need for a second major operation, which would have been necessary in 24% of our patients if treated by a one-stage excisional approach. It is noteworthy that 12% of MIS patients had invasive melanoma in the final excision specimen. This reinforces the importance of adequate full-thickness biopsies of suspicious pigmented lesions before any type of surgical management. With short follow-up, local control has been achieved by this technique in 100% of cases.
