Endometrial echo complex thickness in postmenopausal endometrial cancer.

Objective: To determine the preoperative pelvic ultrasonographic characteristics of postmenopausal women diagnosed with endometrial cancer (EC) at our institution.

Methods: Postmenopausal women with EC who underwent preoperative transvaginal pelvic ultrasound from 1999-2009 were identified from our institutional database. The histologic diagnosis was based on pathologic findings in the hysterectomy specimen. Endometrial echo complex (EEC) thickness was abstracted from ultrasound reports. In all instances, ultrasound preceded the biopsy by a maximum of 3 months. Means with standard deviations were calculated for all categorical data. Differences between type 1 and type 2 ECs were determined using Mann-Whitney U tests and Chi squared/Fisher's exact tests, as appropriate. A p-value of <0.05 was considered statistically significant.

Results: Among 250 patients with postmenopausal EC, 156 had type 1 EC while 94 had type 2 EC. Thirty-six percent of the cohort had an EEC ≤ 4 mm, including 37% of patients with type 1 EC and 34% of patients with type 2 EC (p=0.63). There were no significant differences between type 1 and type 2 ECs in any demographic characteristic, other than likelihood of postmenopausal bleeding.

Conclusions: Current expert opinion recommends no further diagnostic procedure in a woman with postmenopausal bleeding and an EEC ≤ 4 mm. These results indicate that a sizable proportion of women with EC have EECs ≤ 4 mm during their initial evaluation. An EEC ≤ 4 mm does not completely rule out endometrial cancer and cannot supplant histologic evaluation.