A Case of Hair Transplantation in a Nevus Sebaceus Followed by Secondary Tumors, Maintaining the Hair Cycle for Approximately 40 Years

This case study describes a 70-year-old woman with nevus sebaceus (NS) who underwent hair transplantation at age 30, maintaining hair cycling for approximately 40 years despite the development of secondary tumors. The transplanted hair follicles exhibited normal architecture and continued cycling, suggesting that NS-related factors may impair hair morphogenesis but not the hair cycle. Secondary tumors, including desmoplastic trichilemmoma, trichoblastoma, and sebaceous hyperplasia, developed within the NS lesion, indicating that hair transplantation does not eliminate the tumorigenic potential of NS. The study highlights the importance of complete excision as the standard treatment for NS due to its potential for tumor development.