My son is only age 25 and diagnosed with nevus sebaceous and has patches of hairloss on head. Should he have these patches removed?

Nevus sebaceous. An organoid nevus that occurs in 3 of 1000 babies. 50% are on the scalp and 45% are on head and neck. They persist throughout life and enlarge in adult life. The risk for tumor development increases with age and occurs in more than 10% of cases. Both benign and malignant tumors occur. Surgical removal is generally recommended but can be delayed until adulthood.
Nevis. My understanding is that they should be removed as they could become cancerous. Check with a dermatologist.