Notice the ureter’s winding path. During pelvic surgeries, it’s common for the ureter to be cut.
This diagram isn’t anatomically precise (the aorta isn’t at the same level as the rectum), but it does illustrate some important relationships.
ASHERMAN SYNDROME
Scorched earth
Asherman Syndrome is the loss of the regenerative basalis layer of the endometrium. Adhesions fill up the uterus, which becomes scarred, atrophic and useless. Patients will experience amenorrhea (no more periods) and infertility. Basically the only cause is an aggressive D&C (dilation and curettage). A D&C is performed when a pathologist needs tissue from the uterus. First the cervix is dilated, then a little metal instrument called a curette scrapes off a bit of endometrial tissue. Asherman Syndrome occurs if the doctor scrapes off too much endometrial tissue. They have no bleeding from a progesterone withdrawal test. A man scrapes off too much tissue during a D&C, turning the uterus to ash.
ENDOMETRITIS
Uterine infection
Endometritis refers to inflammation of the uterus, but it typically implies a bacterial infection.
Acute Endometritis has one major cause -- retained products of conception (e.g. a piece of fetus remains behind after an abortion) which serves as a nidus for infection (the fetal tissue starts to rot). Foreign bodies (e.g. an IUD) may also serve as a bacterial nidus. There is inflammation (fever) of the endometrium (pelvic pain, vaginal bleeding). This is the most common infection following childbirth. Usually polymicrobial. Treat with Gentamicin plus Clindamycin or Ampicillin.
Chronic Endometritis means there are plasma cells on histology. Be on the lookout for a slow, simmering pelvic inflammatory disease due to Chlamydia. Infertility may occur.
Chronic endometritis. The abundant purple cells in the center are plasma cells.
ENDOMETRIOSIS
Ectopic uterus
Endometriosis refers to the condition where endometrial tissue appears somewhere other than the uterus. The misplaced endometrium still reacts to hormones. Each menstrual cycle, the tissue swells, morphs and bleeds under the influence of estrogen and progesterone. The shed blood can’t drain, leading to build up of pressure (dysmenorrhea) followed by inflammation (scarring, infertility, cancer). Endometriosis is usually found in nearby pelvic tissues, which can get jostled around during sex (dyspareunia).
The dilemma with Endometriosis is that (a) the symptoms are usually pretty vague and (b) there isn’t a good diagnostic test. Diagnosing it can be a real struggle. Endometriosis doesn’t show up on CTs or ultrasounds, so most patients will be initially misdiagnosed multiple times. The diagnosis will be made once the surgeon does an exploratory laparotomy, and sees gunpowder flecks or chocolate cysts.
There are 3 theories explaining the mechanism. (A) Period blood washes back up the fallopian tubes, carrying endometrial cells with it, (B) period blood gets swept up into the lymphatic system, or (C) other adnexal structures undergo metaplasia and morph into endometrial tissue.
Treatment is aimed at dousing the inflammation (NSAIDs), preventing periods (OCPs, GnRH Agonists, Danazol) and finally with surgically cutting out the tissue.
Gunpowder flecks
ENDOMETRIAL HYPERPLASIA
Endometrial hyperplasia refers to growth of the endometrium. It’s driven by unopposed estrogen, which means that there is high estrogen without a correspondingly high progesterone. Endometrial hyperplasia is a bad thing because it can turn into endometrial cancer (the hyperplastic kind).
So where does a surplus of estrogen usually come from?
A progesterone withdrawal test is part of many hormonal workups. By administering progesterone, it helps you identify the patient's estrogen state.
An endometrial polyp is a blob of endometrial tissue growing into the uterine cavity. Polyps are a common cause of painless vaginal bleeding.
ENDOMETRIAL CANCER
Endometrial Carcinoma refers to cancer of the endometrium. The most common presenting symptom is irregular vaginal bleeding. There are two types.
Hyperplastic (or Endometrioid) endometrial carcinoma is caused by rampant unopposed estrogen. See the previous page for more details on unopposed estrogen. The histological appearance looks like normal endometrial tissue (full of glands), albeit more disorganized than usual.
Sporadic (or Papilloserous) endometrial carcinomas are driven by random genetic mutations in one’s lifetime, especially involving a p53 mutation. The sporadic variant results in an atrophic endometrium studded with lots of papillae. These papillae sometimes die and fill up with layers of calcium, which is called a Psamoma body, which is also seen in ovarian carcinomas, papillary thyroid cancer, meningiomas and mesothelioma.
MYOMETRIAL NEOPLASMS
A leiomyoma is a benign myometrial tumor. It’s more commonly called a uterine fibroid, or simply a “fibroid.” They are incredibly common, and can grow quite large (I’ve seen patients with fibroids as large as a beach ball). Fibroids have a very typical appearance. They have a circular shape, white color, well-defined borders and a whorled histological pattern. There are often multiple fibroids growing simultaneously. Their growth is driven by estrogen, so they are more common in young women. They typically fade away after menopause. A beach ball-sized tumor could understandably distort the normal architecture of the pelvis. The mass effect of a fibroid can cause pelvic pain (nerve compression), irregular vaginal bleeding (vascular distortion), infertility (fallopian compression), constipation (rectal compression) and urinary frequency (bladder compression). Symptomatic fibroids can be removed surgically or destroyed by selectively embolizing their blood supply. Importantly, fibroids have no malignant potential!
Whorled histological appearance
Whorled and white grossly
A leiomyosarcoma is a cancer of the myometrium. These are thankfully quite rare. Leiomyosarcomas have a much different appearance than fibroids. They are dark, necrotic, bloody and irregular. The pathologist would find evidence of dysplasia including mitotic figures and koilocytosis.
This is cancer. Notice the mitotic figures (dark squiggles) and inconsistently shaped nuclei.
