This enables the histopathologist to determine the thickness of the melanoma by microscopic examination. This is described by Breslows thickness (measured in millimeters). However, for large lesions, such as suspected lentigo maligna, or for lesions in surgically difficult areas (face, toes, fingers, eyelids), a small punch biopsy in representative areas will give adequate information and will not disrupt the final staging or depth determination. In no circumstances should the initial biopsy include the final surgical margin (0.5 cm, 1.0 cm, or 2 cm), as a misdiagnosis can result in excessive scarring and morbidity from the procedure. A large initial excision will disrupt the local lymphatic drainage and can affect further lymphangiogram-directed lymphnode dissection. A small punch biopsy can be used at any time where for logistical and personal reasons a patient refuses more invasive excisional biopsy. Small punch biopsies are minimally invasive and heal quickly, usually without noticeable scarring. Add on treatment
High-risk melanomas may require adjuvant treatment, although attitudes to this vary in different countries. In the United States, most patients in otherwise good health will begin up to a year of high-dose interferon treatment, which has severe side effects, but may improve the patients prognosis slightly. However, the British Association of Dermatologists guidelines on melanoma state that interferon is not recommended as a standard adjuvant treatment for melanoma. A 2013 meta-analysis suggested that the addition of interferon alpha increased disease-free and overall survival for people with AJCC TNM stage II-III cutaneous melanoma.
A meta-analysis of the literature in 2014 found no randomized controlled trials of surgical interventions to treat lentigo maligna or melanoma in-situ, even though surgery is the most widely used treatment.Mohs surgery has been done with cure rate reported to be as low as 77%, and as high as 95% by another author. The "double scalpel" peripheral margin controlled excision method approximates the Mohs method in margin control, but requires a pathologist intimately familiar with the complexity of managing the vertical margin on the thin peripheral sections and staining methods.Some melanocytic nevi, and melanoma-in-situ (lentigo maligna) have resolved with an experimental treatment, imiquimod (Aldara) topical cream, an immune enhancing agent. Some dermasurgeons are combining the 2 methods: surgically excising the cancer and then treating the area with Aldara cream postoperatively for three months. While some studies have suggested the adjuvant use of topical tazarotene, the current evidence is insufficient to recommend it and suggests that it increases topical inflammation, leading to lower patient compliance. Radiation
Radiation therapy is often used after surgical resection for patients with locally or regionally advanced melanoma or for patients with unresectable distant metastases. Kilovoltage x-ray beams are often used for these treatments and have the property of the maximum radiation dose occurring close to the skin surface. It may reduce the rate of local recurrence but does not prolong survival. Radioimmunotherapy of metastatic melanoma is currently under investigation. Radiotherapy has a role in the palliation of metastatic melanoma.