Uterus - Histology, DUB, Inflammatory Disorders, Ednometriosis Flashcards
(37 cards)
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
