Distinctive pattern of left–right asymmetry of ovarian benign teratomas in Chinese population: a 12-year-long cross-sectional study

PURPOSE: Given the lack of research on the left–right asymmetry of ovarian teratoma among Chinese patients, this study aimed to determine the lateral distribution and related clinical characteristics of Chinese ovarian teratoma patients treated at a single center. METHODS: We conducted a cross-sectional study of surgical patients pathologically diagnosed with ovarian teratomas in the gynecology inpatient department of the International Peace Maternity and Child Health Hospital in Shanghai between July 2006 and July 2018. RESULTS: Of the 4417 patients with ovarian teratoma, 3835 were finally analyzed. There were 2030 (53.24%) cases of right-sided benign ovarian teratoma versus 1783 (46.76%) cases of left-sided benign teratoma (P < 0.001). The recurrence rate of benign ovarian teratoma was 4.2%; recurrence occurred more often on the left side (left vs. right = 55 vs. 45%, P = 0.033). Compared with the right-sided ovarian teratoma patients, left-sided ones had significantly high recurrence risk (OR 1.430; 95% CI 1.03–1.99). The rate of ovarian torsion in patients with ovarian mature cystic teratomas (MCTs) during intrauterine pregnancy was 3.17 versus 1.72% in non-pregnant MCT patients (P = 0.049). For those MCT patients with intrauterine pregnancy, ovarian torsion occurs more often on the right side (left vs. right = 16.67 vs. 83.33%, P = 0.028). CONCLUSION: This study confirms a distinctive right-side dominance of benign ovarian teratomas. Compared with the right side, recurrent ovarian teratomas occur more often on the left side, requiring close follow-up. Intrauterine pregnancy may increase the risk of ovarian torsion, particularly on the right side, in MCT patients.