A 6-year-old boy is brought to the pediatric clinic for evaluation of multiple light brown spots on his skin. His mother reports that she first noticed the spots when he was a baby, but they have increased in number and size over the past few years. On examination, the boy has 7 café-au-lait spots larger than 0.5 cm, axillary freckling, and several soft, fleshy nodules on his back. His father also has a history of similar skin lesions and underwent surgery for a tumor behind his eye. Question: Which of the following is the most likely diagnosis in this patient?
