A 45-year-old woman presents with a pigmented lesion on her right thigh. She undergoes an incisional biopsy which reveals malignant melanoma with a thickness of 3 mm. Findings on examination of the groin are normal. Which of the following is the most appropriate next step in management?

Melanoma with a thickness of 3 mm is managed with a wide local excision with a 2-cm margin. Wide local excision for malignant melanoma with thickness: < 1 mm - 1 cm margin, 1-4 mm - 2 cm margin, > 4 mm - 2 to 3 cm margin This should be followed by sentinel lymph node biopsy. It is the first node that drains a paicular nodal basin. It is identified by: intra-operative injection of blue dye. preoperative injection of 99m Tc sulphur colloid around the lesion and detection with a gamma counter intraoperatively. If this comes positive, it is followed by a complete lymph node (LN) dissection. Malignant Melanoma is a radio-resistant tumor.