What are the clinical characteristics of a fibroadenoma?

Fibroadenomas are the most common palpable mass in patients younger than 35 years.
They are nontender, rubbery, and freely movable.
Typically, fibroadenomas begin in adolescence and may grow to 2 to 3 cm in size.
They may become very large during puberty, in which case they are called juvenile fibroadenomas.