Answer:
Uterine fibroids are nodules of smooth
muscle cells and fibrous connective tissue that develop within the wall of the uterus
(womb). Medically they are called uterine leiomyomata (singular: leiomyoma). Fibroids may
grow as a single nodule or in clusters and may range in size from 1 mm to more than 20 cm
(8 inches) in diameter. They may grow within the wall of the uterus or they may project
into the interior cavity or toward the outer surface of the uterus. In rare cases, they
may grow on stalks or peduncles projecting from the surface of the uterus.The factors that initiate fibroid growth are
not known. The vast majority of fibroids occur in women of reproductive age, and according
to some estimates, they are diagnosed in black women two to three times more frequently
than in white women. They are seldom seen in young women who have not begun menarche
(menstruation) and they usually stabilize or regress in women who have passed menopause.
Fibroids are the most frequently
diagnosed tumor of the female pelvis. It is important to know that these are benign
tumors. They are not associated with cancer, they virtually never develop into cancer, and
they do not increase a woman's risk for uterine cancer.
No one knows how many new cases of
uterine fibroids occur within any given length of time nor how many women have fibroids at
any time. It has been estimated that up to 20 to 30 percent of women of reproductive age
have fibroids, though not all have been diagnosed. More careful studies, however, indicate
that the prevalence may be much higher. A study of 100 uteri that had been removed in
consecutive hysterectomies yielded the following results: 33 had been diagnosed as having
fibroids prior to surgery; routine pathologic examination disclosed that 52 had fibroids.
However, a surprising 77 specimens were found with fibroids upon very close examination.
The majority of the tumors were less than 1 cm in diameter and were missed during routine
pathologic examination. These results indicate that more than three-quarters of women have
uterine fibroids.
This is a small study, however, and
its results should not be interpreted as applying to the entire female population, but as
an indicator that perhaps the prevalence of fibroids is much higher than has been
believed.*
*Cramer,
DW. Epidemiology of Myomas. Seminars in Reproductive Endocrinology 10:320-324, 1992 |
