Benign neoplasms can be multiple, as is shown in this uterus opened anteriorly to reveal leiomyomas of varying size, but they are all benign and well-circumscribed firm white masses. Remember that the most common neoplasm is a benign nevus (pigmented mole) of the skin, and most people have several. As a general rule, without additional transforming influences, benign neoplasms do not give rise to malignant neoplasms.