SM_216b: Pathology of the Endometrium and Uterus Flashcards
Uterus consists of ____ and ____
Uterus consists of endometrium and myometrium

Describe myometrium histology
Myometrium histology
- Mostly smooth muscle (pink solid areas)
- Spindled cells arranged in fascicles at various angles to each other
- Fusiform, blunt-ended nuclei

Endometrium has two regions of mucosa: ____ and ____
Endometrium has two regions of mucosa
- Lower uterine segment / ishmus: not as responsive to hormones
- Uterine corpus: fully responsive to hormones

Two layers of endometrium in the corpus are ____ and ____
Two layers of endometrium in the corpus are basalis and functionalis
- Basalis: lower layer, does not cycle, regenerates endometrium after menses
- Functionalis: top layer, cycles and sheds at menses

Describe the proliferative endometrium
Proliferative endometrium
- Corresponds to ovarian follicular phase
- Response of endometrium to rising estrogen levels
- Glands are simple straight tubules
- Pseudostratified columnar cells
- Mitoses in glands and stromas

Describe the secretory endometrium
Secretory endometrium
- Corresponds to ovarian luteal phase
- Response of endometrium to progesterone (produced by corpus luteum)
- Variable appearance based on cycle day
Early secretory endometrium involves appearance of ____ and has a ____ appearance
Early secretory endometrium involves appearance of vacuoles (subnuclear then supranuclear) and has a piano keys appearance

Midsecretory endometrium involves ___
Midsecretory endometrium involves coiled glands
- Intraluminal secretions
- Stromal edema
- No more vacuoles

Late secretory endometrium involves ____ and ____
Late secretory endometrium involves spiral arterioles and stromal decidualization (large pink stromal cells)
- Sawthooth glands
- Neutrophils and other inflammatory cells

Menstrual endometrium is caused by a ___ and involves ___
Menstrual endometrium is caused by a drop in progesterone and involves a breakdown of glands and stroma
- No pregnancy -> corpus luteum involutes
- Fibrin, necrotic debris, hemorrhage, and inflammatory cells

Atrophic / inactive endometrium results from ___
Atrophic / inactive endometrium results from decreased estrogen levels (usually following menopause)
- Straight tubular glands
- Simple columnar to cuboidal epithelium

____ of endometrium cycles in response to hormones
Functionalis of endometrium cycles in response to hormones
____ phase of endometrium is characterized by vacuoles
Early secretory phase of endometrium is characterized by vacuoles
Non-neoplastic / functional endometrial disorders frequently cause ____
Non-neoplastic / functional endometrial disorders frequently cause anovulatory cycles, chronic endometritis, endometrial polyps, and adenomyosis
Anovulatory cycles appear as ____ on histology
Anovulatory cycles appear as proliferative glands with stromal breakdown on histology (no progesterone to cause secretory differentiation)
- Most frequent cause of dysfunctional uterine bleeding
- Due to hormonal imbalances, endocrine disorders, ovarian lesions, and generalized metabolic disturbances

Chronic endometritis appears as ____ and ____ on histology
Chronic endometritis appears as stromal change (spindling) and plasma cells
- Usually endometrium protected from infection by cervix
- Causes: PID, retained POC, IUD, TB, or other infection
- Acute endometritis is less common and due to infection

Endometrial polyps are ____ that appear as ____ on histology
Endometrial polyps are exophytic masses protruding into the endometrial cavity that appear as epihtelium on three sides with prominent blood vessels, fibrotic stroma, and dilated and irregularly shaped glands on histology

Adenomyosis is ___
Adenomyosis is endometrial glands and stroma within the myometrium
- Similar to endometriosis but confined to myometrium
- Can cause menometrorrhagia, dysmenorrhea, dyspareunia, and pelvic pain

Endometriosis appears as ___, ___, and ___ on histology
Endometriosis appears as endometrial glands, endometrial stroma, and evidence of hemorrhage on histology
- Ectopic endometrial tissue outside the uterus
- Most common sites of involvement: ovary, other pelvic sites, bowel
- Symptoms: infertility, dysmenorrhea, pelvic pain
- Can cause reactive fibrosis and adhesions between organs
- Usually in reproductive age women

Ovarian chocolate cyst and hemosidern-laden macrophages are ____
Ovarian chocolate cyst and hemosidern-laden macrophages are endometriosis

Describe theories of pathogenesis of endometriosis
Theories of pathogenesis of endometriosis
- Regurgitation theory: retrograde menstruation through tubes
- Benign metastasis theory: lymph-vascular spread
- Metaplastic theory: arises from metaplasia of peritoneum (mesothelium)
- Extrauterine stem / progenitor cell theory: stem cells from bone marrow
Top of the differential is ____

Top of the differential is chronic endometritis

Describe endometrial hyperplasia
Endometrial hyperplasia
- Precursor to most common type of endometrial carcinoma
- Increased gland-to-stroma ratio (glands > stroma)
- Associated with prolonged estrogen stimulation
- Inactivation of PTEN tumor suppressor gene in > 20% of hyperplasias
Endometrial hyperplasia classification involves ____ and ____
Endometrial hyperplasia classification involves
- Hyperplasia without atypia / benign hyperplasia
- Atypical hyperplasia / endometrial intraepithelial neoplasia

















