WoW - Single- vs Two-staged Excisions of Thin Melanoma

Inclusion Criteria: Patients need to fulfill all criteria listed below: * Has recently been diagnosed with a primary invasive cutaneous melanoma of Breslow thickness ≤1.0 mm (pT1) as determined by a diagnostic excision with subsequent histopathological analysis that: 1. Is located on a body location in which a WLE with a 10-mm clinical margin is feasible and would have been planned according to current standard of care. 2. Had histopathologically verified free margins of at least 1.5 mm. * Is 18 years or older at time of consent. * Is able to give informed consent and comply with the treatment protocol and follow-up plan. * Has a life expectancy of ≥5 years from the time of diagnosis. Exclusion Criteria: If any of the listed criteria below are present, the patient is ineligible for study participation. The study lesion: * was partially biopsied prior to the diagnostic excision. * was diagnostically excised with a clinical margin \>5 mm. * was a melanoma of desmoplastic or lentiginous (i.e. lentigo maligna or acral lentiginous) subtype. * was located on digits in which amputation is necessary. The patient: * had a previous or concurrent MIS or invasive melanoma (cutaneous or non-cutaneous). * had physical, clinical, radiographic or pathologic evidence of microsatellite, satellite, in-transit, regional or distant metastatic melanoma. * had a previous or intercurrent treated solid tumor or hematologic malignancy during the past 5 years except cutaneous squamous cell carcinoma or basal cell carcinoma. * has planned adjuvant radiotherapy to the primary melanoma site after WLE.