Unexpected malignant uterine pathology: Incidence, characteristics and outcome in a large single-center series of hysterectomies for presumed benign uterine disease.

OBJECTIVE

Hysterectomy is a frequently used therapeutic option for benign gynecological conditions. The purpose of this study was to investigate the incidence and characteristics of unforeseen malignant pathologies of the uterine corpus in a large population-based, single center cohort.

METHODS

Patients who underwent hysterectomy for presumed benign conditions between 2003 and 2016 were identified. In cases of unexpected malignancies of the uterine corpus (UUM), available tissue samples were collected and a specialized gynecopathological review was performed.

RESULTS

A total of 10,756 patients underwent hysterectomy for benign indications. After chart and gynecopathological review, 45/10,756 (0.42%) cases of unexpected uterine malignancies were confirmed. 33/45 (73.3%) were endometrial carcinomas (UEC) and 12/45 (26.7%) were uterine sarcomas (UUS). 27/33 (81.8%) UEC were FIGO IA, 5/33 (15.2%) FIGO IB and 1/33 (3%) FIGO stage II disease. Endometrioid and serous histotype were present in 31/33 (93.9%) and in 2/33 (6.1%) cases, respectively. 8/12 (66.7%) USS were early stage (FIGO IA or IB); only 3/12 (25.0%) were diagnosed at an advanced stage (≥FIGO II). Fatal outcome was observed in 1 patient diagnosed with UEC and 3 patients diagnosed with UUS.

CONCLUSION

Our study shows that diagnosis of UUM is rare (0.42%). The majority of UUM tend to be early stage, making preoperative diagnosis difficult. In case of UEC, patient outcome is generally favorable. Nevertheless, the appropriate surgical approach for hysterectomy for a benign indication should be chosen carefully, taking all preoperative findings into account. Patients should always be informed about the residual risk of UUM.