What is a fibriod?

“Fibroid” is a common lay term used to describe a benign
neoplasm (new growth) that arises from smooth muscle cells.  The medical name of these
benign tumors is “leiomyoma”.  Fibroid is a misnomer in that the tumor consists of
smooth muscle cells rather than fibrous tissue.

Although
leiomyomas can arise in smooth muscle anywhere throughout the body, the term “fibroid”
refers to these lesions when they occur in the uterus
(womb).

The uterus is made up of mostly smooth muscle.  It
has an outer serosa, and an internal cavity lined by endometrium.  At the beginning of
pregnancy the fertilized ovum implants in the uterine endometrial lining.  In a
non-pregnant woman of reproductive age the endometrium sheds cyclically each month as
menstruation.

Uterine leiomyomas (fibroids) are the most
common benign tumor in women.  They occur most often during the reproductive years,
usually sometime after age 20, and are more common in African American women than in
Caucasians. Approximately one in five women will develop fibroid(s) during their
reproductive years.  Fibroids are often multiple, and their size can range from
microscopic to massive.

Within the uterus, fibroids can be
in the uterine wall itself (intramural fibroid), bulging beneath the outer uterine
serosa (pedunculated subserosal fibroid), or immediately beneath the endometrial lining
(submucosal fibroid).

Submucosal fibroids cause abnormal
uterine bleeding between periods.

Intramural fibroids, if
large, can cause a feeling of pelvic pressure, and cramping
periods.

Subserosal fibroids rarely cause symptoms unless
very large.

Diagnosis of fibroids is by pelvic examination,
with confirmation by pelvic ultrasound.

Fibroids do not
become malignant and need not be removed unless they are symptomatic or interfere with
fertility.  The treatment is surgical removal.  Fibroids depend on estrogen for growth,
and symptoms due to fibroids often improve with the use of birth control
pills.