Uterine fibroids are benign (not
cancerous) growths that develop from the muscle tissue
of the uterus. They also are called leiomyomas or
myomas. The size, shape and location of fibroids can
vary greatly. They may be present inside the uterus, on
its outer surface or within its wall, or attached to it
by a stem-like structure. A woman may have only one
fibroid or many of varying sizes. A fibroid may remain
very small for a long time and suddenly grow rapidly or
grow slowly over a number of years.
Fibroids are most common in women aged 30–40 years, but
they can occur at any age. Fibroids occur more often in
African American women than in white women. They also
seem to occur at a younger age and grow more quickly in
African American women.