Uterine Causes of Pelvic Pain and Bleeding

Fibroids are benign (non cancerous) growths or tumors of the uterine wall.  The uterine wall is primarily smooth muscle, and fibroids are tumors of the muscle tissue.  They are common, especially over the age of 30, but can also affect younger women.  They tend to run in families (if your mother or sister have fibroids, then you are more likely to have them also).  Most women with fibroids are not aware of them because they don't cause symptoms.  However, they are a common cause of bleeding- especially those closer to the lining of the uterus (endometrium).  They can also cause cramping bit they don't usually cause severe pain.  

We can describe fibroids by their location within the wall of the uterus.  Fibroids may be predominantly located on the outside surface (subserosal), within the middle of the wall (intramural), adjacent to the lining (submucosal), or within the cavity (intracavitary).  Of course, fibroids don't need to respect these boundaries and usually can be described as a combination of locations- for example, intramural-subserosal may describe a fibroid that is predominantly intramural, but also extends to the outer surface.  Fibroids may also involve  the entire depth of the wall, and I coined the term 'transmural' to describe this location.  

Location, location, location.  We have all heard how important location is.  That's true of fibroids as well when the location of a fibroid can be more important than size.  Very large fibroids on the outer surface of the uterus (subserosal) should not cause bleeding because they are so far from the endometrium, which is the communication of the uterus with the outside world.  Large subserosal fibroids usually don't produce pain either, but they can produce discomfort especially when large enough to push on adjacent structures.

On the other hand, even small fibroids that are submucosal or especially intracavitary in location may produce bleeding as well as cramping.

  Adenomyosis is usually a more diffuse process involving the uterus, unlike the discrete growths of fibroids.  Adenomyosis may be considered as the cells which compose the endometrium or lining into the wall of the uterus.  This may cause both bleeding and pain with your cycle 

  Polyps are benign growths of the lining, or endometrium, similar to fibroids being benign growth of the wall of the uterus.  These are relatively common, but not as common as fibroids.  They may cause intermenstrual bleeding (between periods).  They can be easily overlooked unless specifically sought because they blend in with the normal endometrium  

 Cesarean section scars from prior cesarean deliveries is a much more common cause of pain and bleeding than patients, and physicians, realize.  Unfortunately, our bodies have a memory.  The scar produced from the cesarean incision never goes away completely.  Symptoms of pain and/ or bleeding seem to be more common when the scar is bigger- when it doesn't close completely, or perhaps reopens.  Women with multiple cesarean deliveries have a higher chance of pain.  This can produce scarring along the uterine-bladder interface, and alterations in the appearance of the uterus.    In addition to the scar itself as a source of pain, in some patients endometriosis (growth of endometrial cells) may affect the cesarean scar.  This is not surprising because the incision creates a potential pathway from the endometrium to the outer surface of the uterus. 

We can see a number of findings associated with cesarean incision sites.  

*  We can always see the scar in a woman who has had even one prior cesarean delivery.  

*  We may see fluid or blood extending into a partially open scar.

*  We can see alterations of the uterine contour due to scarring.  The alteration may confuse some sonographers into thinking a fibroid is present, when in fact it just represents the alteration produced by the scarring. 

*  In the most severe cases, we can see alterations and marked thinning of the entire lower uterine wall.  This can produce what I call the 'broken uterus' appearance.

  Any condition that affects the endometrium can cause abnormal bleeding.  This includes over growth (hyperplasia), conditions related to pregnancy, conditions which can irritate the endometrium (for example, an IUD or inflammation), and finally, cancer of the endometrium.  

 A 'tipped' or retroverted uterus is seen in approximately  15% of all patients, but is seen more frequently in patients with pain.  A retroverted uterus does not by itself produce pain.  However, conditions like endometriosis or scarring may 'pull' the uterus into a retroverted position.  Also, consider the anatomy.   Dyspareunia (pain with sexual intercourse) may have many causes but one of these may simply be anatomic.  With a retroverted uterus, the uterus is positioned at the end of the vaginal canal.  This is not the case when the uterus is tipped anteriorly in the 'normal' situation.