Ultrasonographic evaluation of endometrial stripe thickness is insufficient to rule out uterine serous carcinoma

Purpose: Uterine serous carcinoma (USC) is a rare endometrial cancer representing less than 10% of uterine cancers but contributing to up to 50% of the mortality. Delay in diagnosis with this high-grade histology can have significant clinical impact. USC is known to arise in a background of endometrial atrophy. We investigated endometrial stripe (EMS) thickness in USC to evaluate current guidelines for postmenopausal bleeding in the context of this histology. Methods: Retrospective chart review was conducted using ICD-9 and ICD-10 codes over an 18-year period. We included 139 patients with USC and compared characteristics of patients with EMS ≤ 4 mm and EMS > 4 mm. Chi-square or Fisher’s exact tests were used to compare proportions and two-tailed t-tests to compare means. A p-value of < 0.05 was considered statistically significant. Results: Most patients were white, obese, and multiparous. Thirty-two (23%) had an EMS ≤ 4 mm; 107 (77%) had an EMS > 4 mm. There were no statistically significant differences in age at diagnosis or presenting symptoms between groups, and postmenopausal bleeding was the most common symptom in each group. Conclusion: Nearly 25% of patients with USC initially evaluated with transvaginal ultrasound were found to have an EMS ≤ 4 mm. If transvaginal ultrasound is used to triage these patients, one in four women will potentially experience a delay in diagnosis that may impact their prognosis.