Objective To identify the prevalence of unexpected uterine sarcoma after total laparoscopic or abdominal hysterectomy for presumed leiomyoma and compare clinical consequences after hysterectomy with and without transvaginal scalpel morcellation (TVSM).

Methods In this retrospective study, the medical records of patients who had unexpected uterine sarcoma after total laparoscopic or abdominal hysterectomy for presumed leiomyoma between 2009 and 2013 were reviewed.

Results Among 3021 patients who underwent total hysterectomy for presumed leiomyoma, 18 (1/168, 0.60%) had unexpected uterine sarcoma (5 [1/604, 0.17%] had leiomyosarcoma and 13 [1/232, 0.43%] had low-grade endometrial stromal sarcoma). The risk of unexpected leiomyosarcoma increased steadily in ages from the 40s to the 50s, whereas the risk of unexpected endometrial stromal sarcoma (ESS) decreased steadily in the same period. The unexpected sarcoma was identified in 7 (1/158, 0.63%) of 1104 patients treated by laparoscopy and 11 (1/174, 0.57%) of 1917 patients by laparotomy. Transvaginal scalpel morcellation was performed to extract the uterus in majority (78.53%) of the patients with total laparoscopic hysterectomy. Sixteen (88.89%) cases were low grade, and 2 (11.11%) were high grade: 17 at stage I and 1 at stage II. Nine patients underwent a secondary operation, and 11 patients received adjuvant therapy postoperatively. Except for 1 patient with additional power morcellation, all patients with unexpected ESS survived without recurrence after total hysterectomy with and without TVSM, with mean follow-ups of 25.20 (16–36) months and 32.57 (21–50) months, respectively.

Conclusions The overall incidence of unexpected uterine sarcoma after total hysterectomy for presumed leiomyoma was low. Low-grade endometrial stromal sarcoma was the dominant subtype of unexpected uterine sarcoma in the present study. Currently, incidental TVSM of unexpected ESS during total laparoscopic hysterectomy seemed to cause no additional increase in sarcoma dissemination in the short-term.