• CT
• HIPEC
• MRI
• Peritoneal carcinomatosis index
• Peritoneal neoplasms
• Pseudomyxoma peritonei

• Humans
• Peritoneal Neoplasms/diagnostic imaging
• Peritoneal Neoplasms/pathology
• Peritoneal Neoplasms/therapy
• Diagnostic Imaging/methods
• Diagnosis, Differential
• Peritoneum/diagnostic imaging
• Neoplasm Staging

Endometriosis affects approximately 10% of reproductive-age women, however, endometriosis associated malignant transformation is rare and is often report as a rare case.

Herein, we report of a 49-year-old female patient who suffered from severe left lower abdominal pain and imaging examination revealed an irregular mass in the left iliac fossa. Histopathological examination revealed main undifferentiated adenocarcinoma with a few typical endometrial epithelial and stromal tissues in the adjacent area. Combined with the immunohistochemical staining and the negative intra- or postoperative results from exploratory laparotomy, gastroscopy, enteroscopy and positron emission tomography, the tumor was considered to be derived from endometriosis. The patient underwent hysterectomy, bilateral salpingectomy, bilateral ovariectomy, and multipoint biopsy of the pelvic peritoneum. Subsequent radiotherapy and chemotherapy were performed. The patient recovered well post-operation and there was no evidence of recurrence after 10 mo of follow-up via computed tomography and magnetic resonance imaging.

This case highlights a rare presentation of mass-like extragonadal endometriosis associated malignant transformation in the pelvis. Endometriosis associated malignant transformation is rare and difficult to diagnose in clinical settings, with diagnoses depending on pathological results and the exclusion of metastasis from other organs. Fortunately, patients are often diagnosed at younger ages, as well as at early stages; thus they generally have relatively favorable prognoses.

• Endometriosis
• Mass
• Malignant
• Adenocarcinoma
• Case report

The presence of ascites is a common clinical presentation in gynecologic oncology patients. Hemorrhagic ascites (HA) due to endometriosis is a rare presentation that can be easily misdiagnosed as ovarian malignancies. The present study aims to update the currently available knowledge on the characteristics of patients presenting with HA due to endometriosis.

A systematic search was conducted for articles published from January 2000 to July 2020 using the Medline, Scopus, and Google Scholar databases along with the references of the full-text articles retrieved. Papers describing cases of women over 18 years with or without previous history of endometriosis were assessed. Only cases with histologically proven hemorrhagic ascites of endometriosis origin were included.

Twenty-nine studies (27 case reports and two case series) comprising 32 patients were evaluated. The mean patients’ age was 32 years, while six of the patients had a previous history of endometriosis. The mean amount of drained ascitic fluid was 4,200 mL, whereas three patients underwent thoracentesis due to pleural effusions. The treatment options included not only medical but also surgical therapies. Fertility preservation was achieved in 27 patients, while two of them achieved pregnancy with in vitro fertilization (IVF) techniques.

Endometriosis-related hemorrhagic ascites is a relatively rare expression of the disease. Endometriosis-related hemorrhagic ascites should be considered in the differential diagnosis (DD) of women with ascites and clinical suspicion of endometriosis. The available literature is limited to case reports and case series and thus indicates further research in the field to decode the pathophysiology of the disease and decide on the optimal treatment.