Endometrial Cancer Mind Map for OB-GYN Shelf

Written By Manpreet Bindra

START

Why is the patient here?

  1. Postmenopausal bleeding (PMB) → go to A

  2. Premenopausal AUB (esp. ≥45, or <45 with risk factors) → go to B

  3. Incidental thickened endometrium on imaging → go to C

A) POSTMENOPAUSAL BLEEDING (always cancer until proven otherwise)

A1. Stabilize if needed → then evaluate.

A2. First test (stable):

  • TVUS to measure endometrial stripe or office endometrial biopsy (EMB).

    • Exams accept either as initial; know the 4‑mm rule.

A3. TVUS result → action

  • ≤4 mm: low risk → no immediate biopsy; treat likely atrophy. Recurrent/persistent bleeding → EMB.

  • >4 mm or poor visualization → EMB.

  • On tamoxifen with bleeding → EMB regardless of stripe.

A4. EMB result

  • EIN / atypical hyperplasia → Definitive: hysterectomy (if done with childbearing) or high‑dose progestin/LNG‑IUD if fertility desired or poor surgical candidate.

  • Carcinoma → go to E (Stage & Treat).

  • Insufficient/negative but bleeding persists → hysteroscopy ± D&C (target focal lesions).

B) PREMENOPAUSAL AUB (who needs biopsy?)

**B1. Who gets an EMB first?

  • Age ≥45 with AUB.

  • <45 with risk: obesity, PCOS/chronic anovulation, unopposed estrogen (ET‑only HRT), tamoxifen use, Lynch syndrome, early menarche/late menopause, nulliparity.

  • Red flags: intermenstrual bleeding, postcoital bleeding, refractory bleeding.

B2. If not high‑risk and stable:

  • Start with medical AUB mgmt (e.g., OCPs/LNG‑IUD). Persistent AUB → EMB.

B3. EMB positive → go to E.
EMB negative but persistent AUB → hysteroscopy ± D&C.

C) INCIDENTAL THICKENED ENDOMETRIUM

C1. Asymptomatic postmenopausal, stripe >4 mm: no automatic biopsy; observe unless bleeding/risk.
C2. Tamoxifen, no bleeding: no routine screening; biopsy only if bleeding.

D) PATH BASICS (know the types)

  • Type I (endometrioid): estrogen‑driven, often from EIN; better prognosis; PTEN/MMR defects common.

  • Type II (serous/clear cell/carcinosarcoma): p53‑abnormal, aggressive, atrophic background; treat more like high‑risk.

E) CONFIRMED CANCER → STAGE & TREAT

E1. Staging is surgical

  • TAH‑BSO + sentinel lymph node mapping (or pelvic/para‑aortic LND per risk) ± omentectomy for serous/clear cell; peritoneal washings.

E2. FIGO stage (core ideas)

  • I: confined to uterus (IA <50% myometrial; IB ≥50%).

  • II: cervical stroma.

  • III: serosa/adnexa/vagina/nodes.

  • IV: bladder/bowel mucosa or distant.

E3. Adjuvant therapy (pattern you must know)

  • Stage IA, grade 1–2, no LVSI (endometrioid) → observe or vaginal brachy (institutional).

  • Stage IA grade 3 or LVSI; Stage IB–II (endometrioid) → vaginal brachy ± pelvic RT; select chemo (carbo/paclitaxel) if higher risk.

  • Node‑positive / Stage III–IV or Type II histology → chemo (carbo/paclitaxel) ± pelvic/para‑aortic RT.

  • Type II (serous/clear cell) even at earlier stage often gets chemo ± RT.

E4. Fertility‑sparing (high‑yield nuance)

  • Only if: Grade 1 endometrioid, confined to endometrium (no myometrial invasion on MRI/hysteroscopic mapping), no metastasis, patient strongly desires fertility.

    • High‑dose progestin (megestrol) or LNG‑IUD, close surveillance q3–6 mo with repeat sampling. Definitive hysterectomy after childbearing.

E5. Lynch syndrome (MMR/MSI)

  • Universal tumor testing recommended.

  • Proven carriers: counsel for risk‑reducing hysterectomy/BSO after childbearing; earlier colon screening.

“FIRST vs BEST NEXT STEP” CALL‑OUTS

  • PMB (stable): TVUS (≤4 mm = observe) or EMB; >4 mm or recurrent bleeding → EMB.

  • AUB age ≥45 or <45 with risk → EMB first (don’t “just give OCPs”).

  • Visible focal lesion or inadequate sampling with ongoing bleeding → Hysteroscopy ± D&C.

  • Confirmed carcinoma → Surgical staging (TAH‑BSO + nodes), not “chemo first,” unless unresectable/advanced.

  • Young G1 endometrioid, no invasion → Progestin therapy if fertility desired.

NBME TRAPS & REVERSALS

  • Pap smear doesn’t diagnose endometrial cancer. EMB is the test.

  • 4‑mm rule (postmenopause): ≤4 mm → observe; >4 mm → biopsy.

  • Tamoxifen + bleeding → biopsy regardless of stripe.

  • Asymptomatic thick stripe on tamoxifen → no automatic biopsy.

  • PCOS/obesity/anovulation = unopposed estrogen → biopsy threshold is lower.

  • CA‑125 is not a diagnostic test for endometrial cancer (can be prognostic/advanced disease monitoring).

  • Staging is surgical, not clinical (contrast with cervical).

  • EIN/atypical hyperplasia: definitive hysterectomy once fertility complete; progestin/LNG‑IUD if preserving fertility.

Manpreet Bindra

MedRise is a leading educational service focused on empowering medical students, IMG, FMG, residents, and healthcare professionals to succeed. We offer personalized learning solutions, remediation, and career consulting to help individuals achieve their academic and professional goals for the residency match. Our unique approach integrates technology and experience with medical education to create tailored learning experiences, whether you need help preparing for exams, residency applications, or hospital flow processes in GME.

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Cervical Cancer Shelf Study Guide