A Case of Pelvic Actinomycosis with Concomitant Rectovesical and Rectoenteric Fistulas

Abstract

The patient was an 81-year-old woman who had been diagnosed as having adult-onset Still’s disease and was taking oral steroids. She arrived at our hospital with chief complaints of abdominal pain and a fever of 38℃. An examination of blood samples showed a high-grade inflammatory reaction. Abdominal computed tomography findings were suggestive of a tumor in contact with the uterus within the pelvis, and air was observed in the bladder. A vesical fistula caused by the tumor was therefore suspected. No abnormal endometrial findings were observed, and lower gastrointestinal endoscopy findings did not lead to a diagnosis of cancer. The gastrointestinal contrast enema revealed the presence of rectovesical and rectoenteric fistulas. The diagnosis was challenging, but findings suggestive of an abscess in the posterior wall of the uterine cervix were observed on a pelvic MRI. White pus was drained after incision. HE stains showed filamentous gram-positive bacilli, leading to a diagnosis of actinomycosis. High-dose penicillin therapy was administered. We constructed an artificial anus to repetitive urinary tract infection. Here, we report a case of pelvic actinomycosis that was difficult to differentiate from a malignant tumor and presented with concomitant rectovesical and rectoenteric fistulas. We have also included a short discussion of the relevant medical literature in our report.