[Clinical characteristics and risk factors of pelvic mass in women after hysterectomy for benign disease]

Objective: To explore how to reduce the incidence of pelvic mass after hysterectomy, and to evaluate clinical characteristics and the risks. Methods: A retrospective study was carried out in 85 patients who returned for surgery due to a pelvic mass after prior hysterectomy for benign disease at Peking Union Medical College Hospital from January 2011 to June 2016. Results: The majority of pelvic masses arising after hysterectomy and requiring surgery were benign (74%, 63/85), while 19% (16/85) were malignant and 7% (6/85) were borderline. The most common type was ovarian endometrioma (24%, 20/85) which usually occurs within the 5 years (16 cases), however, ovarian tumors (18 cases) were more likely to occur ≥10 years after hysterectomy. Characteristics associated with significantly increased likelihood of ovarian endometrioma were mainly ascribed to younger age [(47±5) years old], prior presence of endometriosis or adenomyosis (65%, 13/20) and shorter time to pelvic mass onset [(3±3) years], as opposed to ovarian tumors (all P<0.01). Additionally, higher number of prior abdominal surgeries significantly intensified the risk (RR=9.410, 95%CI: 1.099-80.564, P=0.041). Conclusions: The occurrence of pelvic mass after hysterectomy is tightly related to prior histologic findings, and particularly for ovarian endometrioma. Higher number of prior abdominal surgery will exacerbated the risk. It is effective to prevent the pelvic mass in women after hysterectomy if treat patients for the purpose of the risk factors.