Background Endometriosis is a common benign gynecological disease characterized by growing-functioning endometrial tissue outside the uterus. Extra-pelvic endometriosis, which accounts for approximately 12% of endometriosis, is more challenging to diagnose because of its distance from the pelvic organs. Halban's theory of benign metastasis indicates that endometrial cells can appear in extra-pelvic organs via lymphatic and blood vessels, but endometrial lymph node metastasis cases are still rare. We report a case of endometriosis in a para-aortic lymph node whose clinical behavior mimicked a malignancy. Case presentation A 52-year-old perimenopausal woman underwent laparoscopic hysterectomy plus bilateral salpingectomy (the patient insisted on the preservation of her ovaries) at a local hospital 2 years earlier because of adenomyosis. The patient presented with a complaint of low back pain to the gastrointestinal outpatient department of our hospital. The carbohydrate antigen 125 (CA125) was abnormally elevated at 5280.20 U/ml, human epididymis 4 (HE4) was 86.0 pmol/L, while other tumor markers were normal. Serum female hormone results were in the postmenopausal range, and her gastroenteroscopy showed no abnormalities. Moreover, both enhanced magnetic resonance imaging and positron emission tomography-computed tomography showed a high possibility of a retroperitoneal malignant lymph node (metastasis possible, primary site unknown). One week after admission, she underwent laparoscopic exploratory surgery, during which we observed normal shape and size of both ovaries while the left ovary was cystic-solid. After opening the retroperitoneal space, an enlarged lymph node-like tissue measuring 8 × 4 × 3 cm3 was found near the abdominal aorta. When the surrounding adhesions were separated, lymph node-like tissue was poorly demarcated from the abdominal aorta and renal artery. Some lymph node samples and left ovary were sent for intraoperative frozen section, which revealed benign lesions, similar to endometrial tissue. The lymph node tissue was then excised as much as possible, and the second set of intraoperative frozen sections showed high probability of endometrial tissue. The final histopathology and immunohistochemistry staining reached a diagnosis of para-aortic lymph node endometriosis. Gonadotropin-releasing hormone antigen treatment was recommended every 28 days because of the high preoperative CA125 and imaging-based suspicion of malignancy. The serum CA125 subsequently decreased to normal levels, and no para-aortic lesions were detected on abdominal enhancement CT. She is being followed up regularly. Conclusion It is known that the incidence of lymph node metastasis in pelvic endometriosis is relatively rare. Our report shows that endometriotic tissue can metastasize via the lymphatic route and suggests that endometriotic tissue has the characteristics of invasion and metastasis.

Background: Ovarian cancer (OC) lacks specific symptoms and screening methods, and most patients are diagnosed at an advanced stage with worse prognosis. Currently, the major treatment approaches for advanced epithelial ovarian carcinoma (AEOC) have been primary debulking surgery (PDS) followed by platinum-based chemotherapy, and neoadjuvant chemotherapy (NACT) followed by interval debulking surgery (IDS). Serum CA125 has been widely used as an indicator for OC diagnosis and management. It is generally believed that preoperative serum CA125 level is associated with tumor burden, and some studies have attempted to evaluate its level to obtain optimal resection rate. HE4 is also a promising biomarker for OC. The aim of the study is to explore whether serum CA125 and HE4 levels in stage III epithelial ovarian cancer predict optimal surgical cytoreductive outcomes. Methods: The clinical data of 201 stage III ovarian cancer patients, diagnosed at our institution from January 2013 to June 2019, were retrospectively collected. According to the initial treatment modality, patients were divided into groups: NACT followed by IDS (89 women) group and by PDS (112 women) group. Differences in patient characteristics were compared using the chi-square test and t-test, and disease-free survival (DFS) was calculated using the Kaplan-Meier method. ROC analysis was used to determine the cut-off values of serum CA-125 and HE4. Results: The medium initial serum levels of CA125 (1359.6 IU/ml vs.759.5 IU/ml, p ˂ 0.001) and HE4 (661 pmol/L vs. 244 pmol/L, p ˂ 0.001) were significantly higher in the NACT group compared with those in the PDS group. Serum CA125 and HE4 levels after NACT decreased by 96.30% and 96.23%, respectively. If the preoperative serum CA-125 value was 500 IU/ml, the probability of achieving R0 was 63.9%. When the preoperative serum HE4 value was 250pmol/L, there was a 65.80% chance of obtaining complete gross cytoreduction. The median DFS was 20 months and 20.5 months in the NACT and PDS groups, respectively. No significant difference in DFS was observed between the two groups (p = 0.851). Conclusion: The efficacy of NACT combined with IDS treatment and PDS for advanced ovarian cancer are comparable. Initial serum CA125 and HE4 levels of 500IU/ml and 250 pmol/L are appropriate cut-off values for predicting the absence of gross residual lesions. CA125 and HE4 values can serve as predictors of optimal surgical cytoreduction. Nevertheless, more clinical studies are needed for further validation.