Adenomyosis and Leiomyomas

MYOMETRIUM 

The myometrium is made of smooth muscle. The cells contain cigar-shapped nuclei, which are elongated and rounded at both ends. The smooth muscle fibers run in all directions (e.g. transverse, oblique, etc.)
 

Adenomyosis

Many women with uterine problems (15-25%) present with this disease. Adenomyosis is the reason for many hysterectomies. 

Adenomyosis is the presence of endometrial glands and stroma in the myometrium. It used to be called endometriosis interna because of its location. However, the endometrium is still connected to the surface; therefore, adenomyosis resembles chronic diverticuli more. 

Adenomyosis can cause a diffuse enlargement of the uterus. This is different from fibroids because no nodules are present. Histologically, punctuate hemorrhagic cysts are present.  

Patients may present with menorrhagia, dysmenorrhea, or no symptoms at all.

Leiomyomas

Leiomyomas are fibroids, the most common type of pelvic tumor. 20% of women over 30 have them. Many women have small fibroids that don’t bother them. 

Leiomyomas are hormonally dependent that grow in the presence of estrogen. The cause is thought to be clonal proliferation of a single cell, usually smooth muscle. Therefore, during menopause, fibroids can shrink. 

Fibroids can be found in three locations:

·         Intramural

o        Fibroids in the uterine wall

·         Subserosal

o        Fibroids are found under the serosa and push it up, giving it a pedunculated look.

o        Subserosal fibroids can be felt as bumps from the outside.

·         Submucosal

o        This causes the most pain out of all the other fibroids because it presses on the endometrium.

o        It can cause bleeding due to the wearing out of the overlying endometrium and cervix. 

Fibroids can outgrow its blood supply and degenerate. Therefore, pregnant women should be careful because fibroids can grow too much and infarct. 

Symptoms from fibroids are dependent upon where the fibroids are located. Symptoms may present as bleeding, pressure, constipation, urinary frequency, or as no symptoms.
 

Leiomyosarcoma is a malignant variant of fibroids. Leiomyosarcomas are very uncommon. It is unsure yet if leiomyosarcomas are malignant changes of fibroids or if they arise de novo. If they are malignant changes, they’re found in less than .5% of all fibroids. 
 

Myomectomy is the removal of fibroids without uterine removal. This is possible because there is a plane of cleavage between the fibroid and the myometrium. The plane of cleavage is called a pseudocapsule because it doesn’t contain any membranous tissue (therefore, pseudo). A pseudocapsule is not present in adenomyosis because adenomyosis is diffuse enlargement. 

Histologically, fibroadenoma is similar to adenomyosis, but with clear cigar-shaped nuclei.

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