Vulvar melanoma represents between 3% and 10% of vulvar neoplasms. We present a case of a 34-year-old pregnant woman presenting with a pigmented lesion on the left labium majus; she reported no family history of melanoma. The histological diagnosis was malignant melanoma, superficial spreading type, with Breslow thickness of 0.9 mm; the excision was complete. Eight months before, an atypical genital nevus was completely excised from a nearby location. The pregnancy was finished by cesarean delivery at term, and 3 months later, another pigmented lesion was noticed near but not within the scars. Partial right vulvectomy was performed, and histological diagnosis was malignant melanoma of superficial spreading type, with Breslow thickness of 0.7 mm. The specimen obtained in the first operation was reviewed, and although histological examination was diagnostic for atypical genital nevus, Vysis Melanoma Fluorescence in situ hybridization Probe Kit revealed increased copy numbers of RREB1, which could be consistent with a diagnosis of malignant melanoma.