Etiologies of Postmenopausal Vaginal Bleeding
Endometrial cancer is the most serious etiology and must be excluded first, though most postmenopausal bleeding has a benign cause. 1, 2
Malignant Etiologies
Endometrial carcinoma is present in approximately 10% of patients with postmenopausal bleeding and represents the primary concern driving urgent evaluation. 3, 4 The peak incidence occurs between ages 65-75 years. 3
Cervical carcinoma can present with postmenopausal bleeding and should be evaluated during speculum examination. 3
Uterine sarcoma risk increases with age, reaching up to 10.1 per 1,000 in patients aged 75-79 years, and must be considered even when fibroids are present. 2
Ovarian cancer may present with bleeding, particularly hormone-producing ovarian tumors. 1, 3
Benign Structural Etiologies
Endometrial atrophy is the most common cause of postmenopausal bleeding overall. 5, 3, 6
Vaginal atrophy causes bleeding from thinned, friable vaginal mucosa and can be identified on speculum examination. 3, 7
Endometrial polyps are common structural causes that can be visualized on transvaginal ultrasound or hysteroscopy. 1, 5, 3
Endometrial hyperplasia (with or without polyps) represents a precursor to endometrial cancer and requires tissue diagnosis. 1, 5, 3
Cervical polyps are easily identified during speculum examination and represent a benign source of bleeding. 3
Submucous leiomyomas (fibroids) can cause bleeding but do not exclude the need to rule out malignancy. 2, 5
Iatrogenic and Medication-Related Causes
Hormone replacement therapy (HRT) and unopposed estrogen use increase bleeding risk and endometrial cancer risk. 8, 3, 4
Tamoxifen (selective estrogen receptor modulator) slightly increases endometrial cancer risk, and any vaginal spotting or bleeding in users requires evaluation. 2, 3
Anticoagulants can contribute to bleeding from underlying pathology. 3
Rare and Unusual Etiologies
Hematological malignancies, particularly chronic lymphocytic leukemia with endometrial infiltration, though rare, should be considered in patients with known blood disorders. 5
Pregnancy can occur in perimenopausal women with sexual activity and should be excluded with β-hCG testing, especially in younger postmenopausal patients. 6
Cervical stenosis with hematometra can cause bleeding when the obstruction releases. 1
Chronic pelvic inflammatory disease with hydrosalpinx or pyosalpinx may contribute to bleeding. 1
Non-Gynecologic Sources
Hematuria from urinary tract pathology can be mistaken for vaginal bleeding. 3
Rectal bleeding from gastrointestinal sources may be misattributed to vaginal bleeding. 3
Critical Risk Factors to Assess
When evaluating postmenopausal bleeding, specific risk factors for endometrial cancer must be identified: 4
- Age (risk increases with advancing age)
- Obesity (unopposed estrogen from peripheral conversion)
- Unopposed estrogen use (HRT without progestin in women with intact uterus)
- Polycystic ovary syndrome (chronic anovulation)
- Type 2 diabetes mellitus
- Atypical glandular cells on cervical cytology
- Family history of gynecologic malignancy or Lynch syndrome
Common Pitfalls to Avoid
Never rely on Pap smear alone to evaluate postmenopausal bleeding, as it screens for cervical cancer, not endometrial pathology. 2
Do not dismiss bleeding in patients with known fibroids without excluding endometrial cancer and uterine sarcoma. 2
Failing to pursue further evaluation when initial endometrial biopsy is negative but bleeding persists can miss malignancy (false-negative rate ~10%). 2