Endometriosis of para-aortic node masquerading a malignancy: a rare occurrence

A Case of Rectal Endometriosis Misdiagnosed as Rectal Malignancy on Three Colonoscopies and Biopsies Sharing a Combined Literature Review

Background

Endometriosis involves the intestine, and its clinical manifestations are nonspecific and lack of etiological manifestations. The diagnosis is difficult, which often leads to misdiagnosis. We report a case of endometriosis which was misdiagnosed as intestinal malignant tumor after colonoscopy and three biopsies.

Case Presentation

We reported a 42-year-old woman who went to see a doctor because of anal distension. She was examined by three gastrointestinal endoscopists at different levels in different hospitals and underwent biopsy at the same time. Combined with clinical manifestations, imaging examination, endoscopic examination and pathological examination, she was misdiagnosed as intestinal malignant tumor, and partial intestinal resection was performed according to the surgical principle of malignant tumor.

Conclusion

Although there are advanced gastrointestinal endoscopy and imaging techniques, intestinal endometriosis is still easy to be misdiagnosed. As our case report shows, after three colonoscopy and biopsy, it is still misdiagnosed as intestinal malignant tumor. Further research is needed to improve the ability of preoperative diagnosis, which deserves the attention of gastroenterologists and obstetricians and gynecologists.

Endometriosis in para-aortic lymph node resembling a malignancy: a case report and literature review

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.