Retrospective analysis of a prospectively collected database (Canadian Task Force III).
Two academic tertiary referral centers.
All cases of ULMS treated at participating institutions between January 2005 and August 2012 were identified following IRB approval.
Abstracted data included demographics, preoperative evaluation, presenting symptom, surgical management, pathology and clinical outcomes. Chi-square tests were used for statistical analysis.
329 cases were identified, of which 152 cases had complete pathologic data available for review. Sixty-eight (45%) of 152 patients had endometrial sampling prior to surgery. Patients with postmenopausal bleeding were significantly more likely to be biopsied preoperatively (51.6% vs 9.5%, p = <.0001). Of those sampled, 43 (63%) underwent endometrial pipelle biopsies and 25 (37%) had dilation and curettage. Endometrial sampling was significantly more likely to detect a concern for malignancy in patients who presented with postmenopausal bleeding (72.7% vs 32.3%, p = 0.002), however it was less likely to detect malignancy in patients with abnormal premenopausal bleeding (31.8% vs 64.3%, p = .02), compared to other presenting symptoms. Overall, 51.5% of patients with ULMS on final pathology had preoperative endometrial biopsies in which leiomyosarcoma or atypical spindle cell proliferation were diagnosed, whereas 35.5% of the pre-operative biopsies identified ULMS specifically.
The sensitivity of an endometrial biopsy to detect ULMS is low, illustrating the difficulty of diagnosing ULMS preoperatively. As expected, the probability that an endometrial biopsy will detect ULMS or a related worrisome pathological finding is higher for patients with post-menopausal bleeding. Thus, benign endometrial biopsy results, particularly in pre-menopausal patients, should be interpreted with caution if there is suspicion for leiomyosarcoma. However, a positive or suspicious result can play an important role in the subsequent management of patients with ULMS, even if the absolute numbers of affected patients are small.