What is the most common form of benign tumors?

Mesodermal in origin. The most common tumor that is benign and virtually remains benign is the lipoma. These increase in number with age. Fibromas are similarly benign and remain as such though in going up the fibrous ladder, the fibromatosis are always benign such as plantar fibromatosis and dermatofibromas. Neuromas of peripheral nerves are also common and remain benign.