Endometrial DisordersJason Ryan, MD, MPH

Uterus • Myometrium: Smooth muscle

• Endometrium: Mucosal surface• Glands and stroma

BruceBlaus/Wikipedia

BruceBlaus/Wikipedia

Glands and Stroma

BruceBlaus/Wikipedia

Endometrium

• Growth and shedding during menstrual cycle

• Estrogen = stimulates growth

• Progesterone = stimulates secretory activity

• Progesterone withdrawal = menstruation

Endometrium

Smallbot/Wikipedia

Myometrium

Endometrium

Endometrium

• Proliferative phase• Estrogen driven

• ↑ glands and stroma

• Secretory phase• Progesterone driven

• ↓ proliferation

• Secretory vacuoles appear

• Prominent spiral arterioles

P. Choudhary

Abnormal Uterine Bleeding

• Abnormal quantity, duration, or schedule• AUB/HMB: Heavy menstrual bleeding

• AUB/IMB: Intermenstrual bleeding

• Polyps

• Adenomyosis

• Leiomyoma

• Malignancy/hyperplasia

• Coagulopathy

• Ovulatory disorders - anovulatory cycle

• Endometrial causes

• Iatrogenic (IUD, drugs)

• NOS

Anovulatory Cycle

• Menstrual cycle without ovulation

• No ovulation → no corpus luteum formation• Absence of luteal phase of ovary

• No switch to progesterone secretion

• Excessive endometrial growth from estrogen

• “Unopposed growth” from lack of progesterone

• Irregular bleeding

Anovulatory Cycle

• Common at menarche • Underdeveloped hypothalamus-pituitary-ovary axis

• Common approaching menopause• Loss of ovulation

• Continued estrogen production

• Also may result from other disorders• Thyroid disease

• Obesity

Endometritis

• Inflammation of the endometrium

• Acute or pregnancy-related

• Chronic or non-pregnancy related

Nephron/Wikipedia

Acute EndometritisPregnancy-Related Endometritis

• Occurs post-partum

• Bacterial infection after delivery or miscarriage

• Key risk factor: cesarean section delivery

• Prophylactic antibiotics used before C-section

• Often also involves myometrium (“metritis”)

• Fever, abdominal pain, uterine tenderness

• Usually diagnosed clinically

Acute EndometritisPregnancy-Related Endometritis

• Polymicrobial infections• Gram positives, gram negatives, anaerobes

• Staph, strep, E. coli, Bacteroides

• Broad-spectrum antibiotics used

• Classic regimen: clindamycin plus gentamycin• Cure rate >90%

• Alternative: ampicillin-sulbactam

RPOCRetained Products of Conception

• Placental/fetal tissue remaining in uterus

• May occur after delivery or miscarriage

• Uterine bleeding and pelvic pain

• Tissue becomes necrotic

• Prone to infection by flora from cervix/vagina

• Leads to acute endometritis

• Diagnosis by history and imaging

• Treatment: antibiotics +/- surgery

Chronic Endometritis

• Intrauterine devices (IUDs)

• Pelvic Inflammatory Disease• Ascending infection

• May involve uterus, fallopian tubes, ovaries

• Salpingitis, oophoritis, endometritis

• Chlamydia or gonorrhea

• Treatment: antibiotics

• Tuberculosis • Hematogenous spread from lungs

• Biopsy: Acid- Fast Bacilli

Chronic Endometritis

• Associated with infertility• Indication for biopsy

• Biopsy hallmark: plasma cells

• White blood cells may be normal in endometrium

• Plasma cell indicates chronic inflammation

Wikipedia/Public Domain

Endometrial Polyps

• Hyperplastic growth of glands and stroma

• Most (95%) benign

• Project from endometrium (“exophytic mass”)

• Often asymptomatic

• May cause painless uterine bleeding

• Removed surgically• Stop bleeding

• Prevent infection

• Small chance malignancy

BruceBlaus/Wikipedia

Endometrial Polyps

• Histology:• Stroma

• Glands

• May see smooth muscle

• Associated with unopposed estrogen

• Common near menopause • Ovarian estrogen production

• Chronic anovulation → lack of progesterone

Tamoxifen

• Selective estrogen receptor modulator (SERM)

• Competitive antagonist of breast estrogen receptor• Used in ER positive (ER+) breast cancer

• Estrogen agonist in other tissues (bone/uterus)

Tamoxifen

• Partial agonist to endometrium

• Endometrial proliferation

• Hyperplasia

• Polyp formation (up to 36% of women)

• May cause endometrial cancer