A 62-year-old G0P0 woman comes to the clinic due to a two-week history of light vaginal spotting. She underwent menopause at age 51 and has not had any vaginal bleeding until now. She has a medical history of hypertension and type 2 diabetes mellitus. Vital signs are within normal limits, and body mass index (BMI) is 34 kg/m2. Pelvic examination shows no visible lesions on the cervix or vagina. A transvaginal ultrasound shows an endometrial stripe thickness of 7 mm.
B) Endometrial biopsy
The gold standard for evaluating postmenopausal bleeding (PMB) is obtaining a tissue sample. In this patient, the transvaginal ultrasound (TVUS) showed an endometrial stripe of 7 mm. Since any measurement > 4 mm in a postmenopausal patient is considered abnormal and associated with an increased risk of endometrial hyperplasia or adenocarcinoma, a biopsy is the mandatory next step.
Answer choice A: Combined oral contraceptive therapy, is incorrect. While progestin or oral contraceptive pills can be used to treat certain types of hyperplasia or dysfunctional bleeding in younger patients, they have no role in the initial diagnostic workup of PMB and could potentially mask a developing malignancy.
Answer choice C: Hysterectomy, is incorrect. While hysterectomy is the definitive treatment for endometrial cancer, a tissue diagnosis is necessary to justify such an invasive procedure.
Answer choice D: Reassurance and observation, is incorrect. Reassurance would only be appropriate if the TVUS showed an endometrial thickness of ≤ 4 mm, which has a very high negative predictive value (nearly 99%) for endometrial cancer. With a 7 mm stripe, the risk is too high to simply observe.
Answer choice E: Repeat ultrasound in 3 to 6 months, is incorrect. PMB is considered endometrial cancer until proven otherwise" Waiting several months to repeat imaging allows for potential disease progression and is not the standard of care when an abnormality has already been identified.
Key Learning Point
In the clinical setting of a postmenopausal patient presenting with new-onset vaginal bleeding, the primary goal is the exclusion of endometrial adenocarcinoma, which is found in approximately 10% of these cases. The diagnostic workup typically begins with either a transvaginal ultrasound or a direct endometrial biopsy. The endometrial strip thickness on ultrasound guides management. A measurement of 4 mm or less suggests that the bleeding is likely due to endometrial atrophy and provides a high negative predictive value for malignancy. If the stripe is greater than 4 mm, or if the ultrasound reveals focal irregularities or an indistinct lining, an endometrial biopsy must be performed to obtain a tissue diagnosis. It is important to note that if a patient continues to experience bleeding despite a "normal" ultrasound, or if they possess significant risk factors such as obesity, chronic anovulation, or tamoxifen use, biopsy remains the gold standard regardless of initial imaging results.
