MYOMA (FIBROID) III—DEGENERATION, OBSTRUCTION
Although the diagnosis of fibroids is generally a clinical one, it must be
remembered that it is impossible to prove, without surgery, either the
suspected diagnosis of a fibroid uterus or the assumption that such a tumor may
be the cause for symptoms; ovarian neoplasms occasionally adhere to and invade
the fundus posteriorly and present a mass with misleading characteristics; and
bleeding may be caused by an endocrine dysfunction. After the menopause, such
bleeding from a benign endometrial hyperplasia may be a telltale sign of a
functioning ovarian tumor that might be overlooked unless it is recalled that
fibroids almost never initiate bleeding in the postmenopausal period and
certainly never cause endometrial proliferation.
Many factors play a role in each patient’s decision of management. Justification for multiple myomectomy is found in those desiring to preserve the chance of pregnancy. In those with abnormal bleeding and small fibroids at the climacteric, after the possibility of cancer has been investigated by endometrial biopsy or curettage, the diagnosis of anovulatory cycles may suggest hormonal therapy, with the hope that the complaint may be controlled until ovarian function ceases. Uterine artery embolization may be used for patients who are not surgical candidates or those who wish to preserve fertility. (Successful pregnancy is possible, but because uterine embolization has been associated with a number of both short- and long-term complications, it is considered experimental in women who desire fertility.) If the cervix has been the site of persistent atypia, or if cystocele or rectocele or uterine prolapse is present, then in those women beyond an interest in childbearing, it is wise to remove a fibroid uterus as a part of the reconstruction of a firm pelvic floor. Occasionally and unfortunately, a patient may be told that she has a tumor, and she may become so concerned with undue anxiety with regard to cancer that no choice is left in order to set her mind at rest but operative removal of the fibroids.
At times, a large fibroid may outgrow its blood supply, with resultant
cystic degeneration. The arterial supply of myomas is significantly less than
that of a similarly sized area of normal myometrium. As a result, degeneration
occurs when the tumor outgrows its blood supply. The severity of the
discrepancy between the myoma’s growth and its blood supply determines the type
of degeneration: hyaline, myxomatous, calcific, cystic, fatty, or red
degeneration and necrosis. The mildest form of degeneration of a myoma is
hyaline degeneration. Grossly, in this condition the surface of the myoma is
homogeneous with loss of the whorled pattern. Histologically, with hyaline
degeneration, cellular detail is lost as the smooth muscle cells are replaced by fibrous connective tissue.
A large fibroid originating from a sharply retroverted fundus may become
incarcerated in the hollow of the sacrum, pressing on the rectum, causing
obstipation, although obstruction from this cause is probably rare. A similar
situation is pictured as resulting from a fibroid arising posteriorly from the
endocervical region.
Cervical fibroids in the uterus at term may retract upward as cervical dilation proceeds, allowing for an uncomplicated delivery, or they may be forced downward, causing dystocia and making delivery impossible. Rarely, the high levels of both growth and ovarian hormones can stimulate existing fibroids to grow rapidly during mid-to late pregnancy, resulting in problems for the pregnancy. This rapid growth may be associated with pain, especially when the growth outstrips the available blood supply and degeneration or necrosis ensues. This form of degeneration occurs in approxi-mately 5% to 10% of gravid women with myomas.
