STEPTRACKERREPRODUCTIVE | PATHOLOGY + ENDOCRINE | HIGH-YIELD REVIEW

Endometrium

Unopposed estrogen and what it builds, two kinds of endometrial cancer, and endometrial tissue in places it shouldn't be.

FOCUS ON
Postmenopausal bleeding = endometrial carcinoma until biopsy proves otherwise. Endometrioid (type 1): unopposed estrogen → hyperplasia → carcinoma; obese, PTEN, Lynch. Serous (type 2): older thin women, atrophic endometrium, TP53, aggressive. Endometriosis: glands outside uterus, pain + infertility, normal-sized uterus. Adenomyosis: glands in myometrium, big boggy uterus.
DISORDER
MECHANISM · RISK
FEATURES
CLUE · TREATMENT
Endometrial hyperplasia
Unopposed estrogen: obesity (aromatase in fat), PCOS/anovulation, estrogen-only HRT, tamoxifen, granulosa cell tumor; PTEN loss
Abnormal or postmenopausal bleeding; crowded glands
Atypia is the strongest predictor of cancer · progestins or hysterectomy
Endometrioid carcinoma (type 1)
most common gynecologic cancer in US
Estrogen-driven, arises from atypical hyperplasia; PTEN, PIK3CA, KRAS, mismatch repair (Lynch)
Perimenopausal/postmenopausal obese women; postmenopausal bleeding
Low grade, good prognosis
Serous carcinoma (type 2)
Not estrogen-related; arises in atrophic endometrium; TP53
Older, thin women; papillae, psammoma bodies; spreads early through tubes to peritoneum
Aggressive, poor prognosis
Carcinosarcoma (MMMT)
Biphasic: malignant epithelium + sarcoma (may contain cartilage, muscle)
Older women; bulky polypoid mass protruding from the cervix
Pelvic radiation, tamoxifen · very aggressive
Endometrial polyp
Localized overgrowth of glands and stroma; tamoxifen
Intermenstrual or postmenopausal bleeding
Usually benign · hysteroscopic removal
Endometriosis
Endometrial glands + stroma outside the uterus: retrograde menstruation, coelomic metaplasia, lymphatic spread
Cyclic pelvic pain, dysmenorrhea, dyspareunia, dyschezia, infertility; normal-sized uterus
NSAIDs, OCPs, progestins, GnRH agonists · laparoscopy diagnoses
Endometriosis — sites
Cyclic bleeding into ectopic tissue → fibrosis, adhesions
Ovary: "chocolate cyst" (endometrioma) · peritoneum: "powder-burn" lesions · uterosacral ligaments (fixed retroverted uterus)
↑ endometrioid and clear cell ovarian carcinoma
Adenomyosis
Endometrial glands and stroma within the myometrium
Dysmenorrhea, menorrhagia; uniformly enlarged, soft, globular uterus; multiparous women in 40s
Hysterectomy is definitive
Acute endometritis
Ascending infection after delivery (especially C-section) or retained products
Fever, uterine tenderness, foul lochia
Clindamycin + gentamicin
Chronic endometritis
Retained products, PID, IUD, TB
Abnormal bleeding, pain, infertility; plasma cells in endometrium
Plasma cells define it
Asherman syndrome
Destruction of the basalis (D&C, infection) → intrauterine adhesions
Secondary amenorrhea, infertility; no withdrawal bleed after estrogen + progestin
Hysteroscopic adhesiolysis

Mechanism — unopposed estrogen

Estrogen without progesteroneObesity, anovulation, HRT
→
ProliferationNo secretory switch
→
Hyperplasia± atypia
→
Endometrioid carcinomaPTEN, MMR

Protective: combined OCPs, progestins, smoking (antiestrogenic), multiparity. Tamoxifen is an estrogen agonist in the endometrium.

Type 1 vs type 2 endometrial carcinoma

FEATURE
ENDOMETRIOID (1)
SEROUS (2)
Patient
Peri/postmenopausal, obese
Older, thin
Background
Hyperplasia
Atrophy
Estrogen
Driven by it
Independent
Genes
PTEN, MMR, PIK3CA
TP53
Prognosis
Good
Poor
Endometriosis vs adenomyosis
Endometriosis: outside the uterus, uterus normal size, infertility · adenomyosis: inside the myometrium, uterus big and boggy, heavy bleeding.

How it's tested

COMMON CONFUSIONLeiomyomas make the uterus big and irregular; adenomyosis makes it big, soft and symmetric.
THE TRAPEndometrial cancer can occur in a thin older woman with no estrogen excess — serous carcinoma arises in atrophic endometrium and is aggressive.
YOUR APPROACHBleeding pattern + age + estrogen exposure → biopsy (hyperplasia, atypia, carcinoma type). Pain + infertility → endometriosis; heavy bleeding + boggy uterus → adenomyosis.

If you see… think…

Obese 58-year-old with postmenopausal bleeding → endometrioid carcinoma — biopsy
PCOS with years of anovulation and thick endometrium → endometrial hyperplasia
Hyperplasia feature that predicts cancer → cytologic atypia
Thin 75-year-old, papillary tumor with psammoma bodies, TP53 → serous carcinoma
Breast cancer patient on tamoxifen with vaginal bleeding → endometrial polyp / hyperplasia / carcinoma
Lynch syndrome woman's most common extracolonic cancer → endometrial carcinoma
Cyclic pelvic pain, infertility, chocolate ovarian cyst → endometriosis
Multiparous 45-year-old, heavy painful periods, large boggy uterus → adenomyosis
Plasma cells in an endometrial biopsy → chronic endometritis
Amenorrhea after repeated D&C → Asherman syndrome