Objective: To define the incidence of unexpected gynecologic malignancies among women who underwent hysterectomy for benign indications.
Methods: We conducted a data analysis of hysterectomy cases from a quality and safety database maintained by the Michigan Surgical Quality Collaborative, a statewide group of hospitals that voluntarily reports perioperative outcomes. Cases were abstracted from January 1, 2013, through December 8, 2013. Benign preoperative surgical indications included pelvic mass, family history of cancer, hyperplasia without atypia, prolapse, endometriosis, pelvic pain, abnormal uterine bleeding, or leiomyomas. Women with a surgical indication of cancer, cervical dysplasia, or hyperplasia with atypia were excluded.
Results: During the study period, 7,499 women underwent a hysterectomy and 85.24% (n = 6,360) were performed for benign indications. The incidence of unexpected gynecologic malignancy among hysterectomies performed for benign indications was 2.7% (n = 172) and included ovarian, peritoneal, and fallopian tube cancer (n = 69 [1.08%]), endometrial cancer (n = 65 [1.02%]), uterine sarcoma (n = 14 [0.22%]), metastatic cancer (n = 13 [0.20%]), and cervical cancer (n = 11 [0.17%]). The most common indications for hysterectomy were leiomyomas and abnormal uterine bleeding. There was no difference in the mean age (46.86 ± 10.57 compared with 47.0 ± 10.76 years, P = .96) of women with unexpected sarcoma compared with benign disease. Women with unexpected sarcoma were more likely to have a history of venous thromboembolism and preoperative blood transfusion, but this did not reach statistical significance.
Conclusion: The 2.7% incidence of unexpected gynecologic malignancy includes a 0.22% incidence of uterine sarcoma and 1.02% incidence of endometrial cancer. No reliable predictors of uterine sarcoma exist and caution is warranted in preoperative planning for hysterectomy.