Leiomyomas (fibroids) are the most common
tumours of the uterus
Leiomyomas, also called fibroids, are the most common benign tumours of the
female genital tract. They affect over half of all women over the age of 30,
usually becoming symptomatic in the decade before the menopause.
Macroscopically, leiomyomas appear as rounded, rubbery, pale nodules, which have
a whorled appearance on cut surface. They may arise in several locations within
the uterus (e.g. intramural, sub-mucosal, polypoid sub-mucosal, and sub-serosal)
and are very commonly multiple.
Leiomyomas vary in size, ranging from under 1 cm in diameter to giant lesions
that are 20-30 cm in size. The typical diameter for lesions responsible for
clinical problems is 2-4 cm.
Histologically, tumours are composed of smooth-muscle cells and intervening
collagenous stroma. Importantly, there is no cellular atypia and very few
mitoses are seen. Several uncommon histological variants of leiomyoma are also
described, characterized by unusual cellular or stromal patterns, e.g. myxoid
change.
Degenerative changes and complications occur in these tumours. For example,
tumours may outgrow their blood supply, becoming replaced by hyaline material,
as well as undergoing calcification. In pregnancy, and less commonly at other
times, tumours may develop ischaemic degeneration in which lesions become soft
and uniformly dark red (so-called 'red degeneration').
Pedunculated tumours may
undergo torsion, developing venous infarction.
Clinically these tumours are associated with abnormal menstrual bleeding,
dysmenorrhoea, or infertility. Occasionally they cause problems because of their
effects as a large abdominal mass, e.g. compressing the bladder. During
pregnancy, leiomyomas may cause complications such as spontaneous abortion,
premature labour, and obstruction of labour.
Uterine leiomyomas depend on the trophic action of oestrogen for maintenance of
size, and tumours usually shrink after the menopause. Treatment with GnRH-agonists,
which induce hypo-oestrogenism, is being used to cause shrinkage of the uterus
and fibroids to allow easier surgical removal by myomectomy. For most women who
no longer wish to conceive, the treatment is to have a hysterectomy.
Tumours of the fallopian tube are very uncommon
Salpingitis is an important cause of late tubal obstruction and infertility
Salpingitis is nearly always caused by infection that has gained access by
ascending from the uterine cavity. Most cases result in acute salpingitis with
acute inflammation, but others result in a chronic inflammatory reaction.
The main associations for salpingitis are following pregnancy and endometritis,
IUCD use, sexually transmitted disease (Mycoplasma, Chlamydia and gonococcus),
TB, and Actinomyces.
In cases of acute salpingitis, the tubes are macroscopically swollen and
congested, with a red, granular appearance to the serosal surface, due to
vascular dilatation. Histologically the lumen may contain pus and there is
infiltration of the tubal epithelium by neutrophils. A pyosalpinx occurs when
there is massive distension of the tubal lumen by pus.
Chlamydial colonization of the tubal mucosa is increasingly being recognized as
a cause of impaired tubal function in infertile women, and this is usually in
the absence of symptoms and laparoscopic signs of active infection. The
histological correlates of such infection are uncertain.
Tuberculous salpingitis is acquired by haematogenous spread from a site outside
the genital tract.
The tubes develop multiple granulomas in the mucosa and wall,
causing adhesions to adjacent tissues (especially ovary).
In advanced cases the
tube may be converted to a cavity filled with caseous necrotic material.
Infection by Actinomyces is predisposed by colonization of the female genital
tract in association with IUCD use. The pus in the tubal lumen contains colonies
of Actinomyces, visible macroscopically as 'sulphur granules'.
In many cases of infection of the fallopian tube, adhesions form between the
tube and the ovary, and infection involves the tube, ovary and adjacent
parametrial tissues. This situation gives rise to a matted clump of tissue and
fibrosis, referred to as a tubo-ovarian mass, in which individual components are
hard to discern.
Hydrosalpinx is dilatation of the fallopian tube, with flattening of the mucosa,
the lumen being distended by clear, watery fluid. This is believed to be a
sequel to previous inflammatory damage to the tube, acquired with healing of
previous inflammation . |
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