Three cases of ovarian actinomycosis with literature review.

Background: Actinomycosis is an actinomycete infection, a rare zoonotic disease characterized by chronic suppurative inflammation and granulomatous inflammation. When injury occurs to the mucosa where parasites are present, actinomycetes can invade the mucosa. Widespread use of intrauterine devices (IUDs) has increased the incidence rate of pelvic actinomycosis among women. The clinical manifestation of ovarian actinomycosis is mostly a solid or cystic ovarian mass, which can invade surrounding tissue and may be accompanied by elevated levels of the tumor marker cancer antigen 125 (CA125). Therefore, ovarian actinomycosis is easily misdiagnosed as a malignant ovarian tumor.

Case description: Three cases of ovarian actinomycosis diagnosed in the Department of Pathology of the West China Second University Hospital of Sichuan University from January 2020 to March 2022 were retrospectively analyzed. All 3 patients had a history of IUD implantation for more than 10 years. All patients presented with abdominal masses and abdominal pain. One patient had weight loss, and 2 patients had elevated tumor marker CA125. Imaging results showed that all patients had ovarian space-occupying lesions involving the surrounding tissue; therefore, all patients were suspected to have malignant ovarian tumors before surgery. All 3 patients underwent surgical treatment. Specifically, 1 patient underwent bilateral salpingo-oophorectomy, and 2 patients underwent total hysterectomy and bilateral salpingo-oophorectomy. All patients received high-dose antibiotic treatment after surgery, and thus far, relapse has not been observed. Postoperative pathologicexamination showed purulent inflammation and sulfur granules, consistent with ovarian actinomycosis. Anaerobic culture was positive for 1 patient.

Conclusions: Ovarian actinomycosis is closely related to long-term IUD implantation. The clinical manifestations and imaging features of this disease are not specific; therefore, preoperative diagnosis is difficult. The disease is easily misdiagnosed as ovarian cancer. Sulfur granules are signs of ovarian actinomycosis, and thus, those with this manifestation should be carefully screened by pathologic examination. Surgery combined with antibiotic treatment is effective for ovarian actinomycosis, resulting in a good prognosis.