Nodular melanoma complicating congenital melanocytic nevus

History

       A 75-year-old man presented with a small dark-red to brownish dome-shaped slightly crusted nodule developed within an irregularly-shaped congenital melanocytic nevus. The nodule has been noticed six months before presentation. It has been excised with a suitable safe margin and sent for histologic examination which revealed a nodular melanoma with malignant melanocytes reaching to mid dermis level.