What is the approach to a patient with postmenopausal bleeding?

Approach to Postmenopausal Bleeding

Begin with transvaginal ultrasound (TVUS) to measure endometrial thickness, proceeding to endometrial biopsy if thickness is >4 mm or if bleeding persists despite a thin endometrium. 1, 2

Initial Diagnostic Pathway

First-Line Imaging

• TVUS is the recommended first-line test to measure endometrial thickness and identify structural abnormalities of the uterus, endometrium, and ovaries 1, 2
• An endometrial thickness ≤4 mm carries a negative predictive value for cancer of nearly 100%, allowing expectant management 1, 2
• If endometrial thickness is ≥5 mm, tissue sampling is mandatory 2

Tissue Diagnosis

• Office endometrial biopsy is the standard method for histological assessment when indicated by ultrasound findings or persistent bleeding 1, 2
• The sensitivity for detecting endometrial carcinoma is 99.6%, though it carries approximately a 10% false-negative rate 1, 2
• This false-negative rate necessitates further evaluation when bleeding persists despite negative initial biopsy 1, 2

Management of Persistent or Non-Diagnostic Results

When Initial Testing is Inadequate

• If office endometrial biopsy is negative but bleeding persists, or if the biopsy is non-diagnostic, perform fractional dilation and curettage (D&C) under anesthesia 1, 2
• Hysteroscopy is helpful for evaluating the endometrium for focal lesions such as polyps in patients with persistent or recurrent undiagnosed bleeding 1, 2
• Saline infusion sonography can distinguish between focal and diffuse endometrial pathology, particularly useful in patients with tamoxifen use or estrogen therapy 1, 2

Alternative Imaging

• MRI should be considered if TVUS cannot adequately evaluate the endometrium due to patient factors (obesity, inability to tolerate transvaginal probe) or pathology such as fibroids or adenomyosis 1, 2

Risk Stratification and High-Risk Features

Patients Requiring Aggressive Evaluation

• Age >50 years (>90% of endometrial cancers occur in this age group) 1
• Obesity (BMI >30) 1
• Unopposed estrogen exposure 1
• Tamoxifen use 1
• Lynch syndrome (lifetime endometrial cancer risk of 30-60%) 3, 1
• Nulliparity, diabetes mellitus, or hypertension 1

Special Populations

• Women on tamoxifen require annual gynecologic assessment and must report any vaginal spotting immediately due to increased endometrial cancer risk 1, 2
• Women with Lynch syndrome should be educated about the importance of prompt reporting and evaluation of any abnormal uterine bleeding, with endometrial biopsy as the diagnostic procedure of choice 3
• Endometrial sampling is mandatory when abnormal bleeding occurs in women with a uterus on estrogen therapy 1

Critical Pitfalls to Avoid

Common Diagnostic Errors

• Never rely on Pap smear for evaluation of postmenopausal bleeding—it screens for cervical cancer, not endometrial pathology 2
• Do not use endometrial thickness cutoffs higher than 4 mm, as this may miss cases of endometrial cancer 2
• Even in the presence of fibroids, uterine sarcoma and endometrial cancer must be ruled out, particularly in older patients where the risk of unexpected uterine sarcoma reaches 10.1 per 1,000 in patients aged 75-79 years 1, 2
• Failing to pursue further evaluation when initial tests are negative but bleeding persists is a critical error 2

Differential Diagnosis to Consider

Malignant Etiologies

• Endometrial cancer is the most serious etiology and must be excluded first 2
• Ovarian cancer, particularly hormone-producing tumors, may present with bleeding 2

Benign Etiologies

• Endometrial polyps (visualized on TVUS or hysteroscopy) 2
• Endometrial hyperplasia, which represents a precursor to endometrial cancer and requires tissue diagnosis 2
• Atrophic endometrium (most common benign cause) 4
• Cervical stenosis with hematometra 2