Uterus - Histology, DUB, Inflammatory Disorders, Ednometriosis Flashcards
What will patients complain of that may suggest that the uterus is the culprit?
- Infertility or pregnancy
- Amenorrhea, dysmenorrhea
- Discharge –> blood
- Pain
- A recurrence or other medical condition
- Systemic disease or syndrome
What happens to the endometrium during the menstrual cycle?
- Undergoes dynamic physiologic and morphologic changes in response to sex steroid hormones produced in the ovary
- Ovary is influenced by hormones produced by the pituitary due to signals from the hypothalamus
What are the two major components of the uterus?
- Myometrium
- Endometrium
What is the myometrium composed of?
- Tightly interwoven bundles of smooth muscle that form the wall of the uterus
What is the endometrium composed of?
- Glands embedded in a cellular stroma
- Lines the internal cavity of the uterus
What are the most common disorders that affect the uterus?
- Endocrine imbalances
- Complications of pregnancy
- Neoplastic proliferation
Why is the histology of the endometrium important?
- Can be used to assess hormonal status, document ovulation, and determine causes of endometrial bleeding and infertility
What is the first five days of a menstrual cycle?
- The menstrual phase
What occurs during the menstrual phase?
- Initiated with the dissolution of the corpus luteum and the subsequent drop in progesterone levels –> functionalis layer degenerates/shed
What is the the proliferative phase?
- Day 5-14
- Marked by rapid growth of glands and stroma arising from the deeper portion of the endometrium
- Glands are straight, tubular structures lined by regular, tall, pseudostratified columnar cells
What is the endometrial stroma composed of?
- Spindle cells with scant cytoplasm that are also actively proliferating
When is ovulation?
- Day 14 in the cycle
What marks post ovulation?
- Appearance of secretory vacuoles beneath the nuclei in the glandular epithelium (subnuclear vacuoles)
What happens during the secretory phase?
- Progesterone down-regulates the expression of estrogen receptor in both the glands and the stroma
- The result is suppressed endometrial proliferation
What happens during the fourth week of the cycle, during the later half of the secretory phase?
- Basal vacuoles progressively move towards the apical surface
- Glands become more tortuous and produce a serrated appearance (saw tooth) –> accentuated by secretory exhaustion and shrinkage of the glands
How does the stroma change in the late half of the secretory phase?
- Predominantly due to progesterone
- Stromal cell hypertrophy
- Increased ground substance and edema
- Cytoplasmic eosinophilia
What is the most common cause for dysfunctional uterine bleeding?
- Anovulatory cycle
What is dysfunctional uterine bleeding?
- Bleeding that is not associated with an underlying structural abnormality
What are some less common causes of dysfunctional uterine bleeding?
- Generalized metabolic disturbances (obesity, malnutrition, other chronic systemic diseases)
- Ovarian lesions (functioning tumors, polycystic ovary disease)
- Endocrine disorders (thyroid, adrenal, pituitary)
What could failure of ovulation result in?
- Excessive endometrial stimulation by estrogens that is unopposed by progesterone
What could repeated anovulation result in?
- Bleeding that may prompt an endometrial biopsy
What are some structural causes of heavy menstrual bleeding (HMB)?
- PALM
- Polyps (endometrial or cervical)
- Adenomyosis
- Leiomyoma
- Malignancy and hyperplasia
What are some nonstructural causes of HMB?
- COEIN
- Coagulopathy
- Ovulation dysfunction
- Endometrial (primary disorders of the endometrium)
- Iatrogenic
- Not yet classified
Why is the endometrium and myometrium relatively resistant to infections?
- Endocervix forms a barrier to ascending infection
- Chronic inflammation in the cervix is common and usually insignificant
What is the cause of acute endometritis?
- Uncommon but limited to bacterial infections that arise after delivery or miscarriage
What are the predisposing factors for acute endometritis?
- Retained products of conception
What are the causative agents in acute endometritis?
- Group A hemolytic strep
- Staphylococci
- Other bacteria
What is chronic endometritis associated with?
- Chronic pelvic inflammatory disease
- Retained gestational tissue, postpartum or post abortion
- Intrauterine contraceptive devices
- TB (either from miliary spread or drainage of tuberculous salpingitis)
- No cause identified in 15%
What is a major diagnostic feature of chronic endometritis?
- Presence of plasma cells on histology
What are some symptoms of endometriosis?
- Infertility
- Dysmenorrhea
- Dyspareunia
- Pelvic pain
What are some symptoms of adenomyosis?
- Menometrorrhagia
- Colicky dysmenorrhea
- Dyspareunia
- Pelvic pain
What is endometriosis?
- Presence of ectopic endometrial tissue at a site outside the uterus
- Commonly includes both glands and stroma but sometimes could only be stroma
What are some sites of endometriosis?
- Ovaries
- Uterine ligaments
- Rectovaginal septum
- Cul de sac (rectouterine pouch of Douglas)
- Pelvic peritoneum
- Large and small bowel of appendix
- Mucosa of cervix, vagina, and fallopian tubes
- Laparotomy scars
What is adenomyosis?
- Presence of endometrial tissue within the uterine wall
What is the pathogenesis theories of endometriosis?
- Regurgitation theory - Retrograde flow of menstrual endometrium thru the fallopian tubes
- Benign metastasis theory - endometrial tissue spreads via blood vessels and lymphatic channels
- Metaplastic theory - Endometrium arises from coelomic mesothelium or mesonephric remnants that undergo endometrial differentiation
- Extrauterine stem/progenitor cell theory - bone marrow derived stem/progenitor cells differentiate into endometrial tissue
What do the stromal cells in ectopic endometrial tissue produce?
- Estrogen due to high levels of aromatase and increased retinoic acid
How is endometriosis diagnosed?
- Clinical/Ultrasound/Laparoscopically
- Bleeding periodically/cyclically that produces red/blue to yellow/brown nodules on or beneath the mucosa or serosa (powder burn marks)
- When extensive, can cause fibrous adhesions
