Ovarian Clear Cell Carcinoma and Rectal Adenocarcinoma Detected by Tubo-Ovarian Abscess: A Case Report.

Most cases of tubo-ovarian abscess (TOA) are due to transvaginal infection, while other internal diseases may also be associated with TOAs. We experienced a case of ovarian clear cell carcinoma and rectal carcinoma that was discovered to be a result of TOA. A 46-year-old woman was diagnosed with TOA and referred to our hospital. Laparoscopic abscess drainage was performed, and pathological findings confirmed the presence of ovarian clear cell carcinoma inside the abscess. The tumor marker carcinoembryonic antigen (CEA) was elevated, and rectal cancer was diagnosed by a gastrointestinal endoscopy. Abdominal computed tomography (CT) showed a left adnexal abscess with an air image inside, and penetration of the abscess wall and rectal cancer were observed. Histopathologically, there was an accumulation of neutrophils around the rectal tumor cells. We concluded that the rectal cancer had penetrated the existing ovarian tumor and formed TOA. Non-gynecological diseases may be associated with TOA. It is necessary to consider the possibility that other clinical diseases may be associated with the trigger of TOA.