A rare case of abdominal actinomycosis mimicking ovarian cancer with presumed hepatic involvement and abdominal wall involvement

species. Because of its infiltrative growth, abscess formation, and fibrotic reaction, it may closely mimic malignant disease. We report the case of a 53-year-old woman presenting with abdominal pain and a palpable epigastric mass. Imaging showed a pelvic mass with abdominal wall involvement and a hepatic lesion, initially suggestive of advanced pelvic malignancy. Tumor markers were within normal limits. Because of persistent diagnostic uncertainty, the patient underwent elective exploratory laparoscopy with biopsy. Intraoperative findings showed a firm pelvic mass involving the right adnexa and uterus, without a clear tissue plane. Frozen-section examination initially suggested a small-cell neoplasm, whereas definitive histological examination confirmed abdominal actinomycosis. The hepatic lesion was not biopsied; therefore, hepatic involvement was considered presumptive, based on the radiological findings and complete regression after prolonged antibiotic therapy. Long-term intrauterine device use represented a relevant predisposing factor. Abdominal actinomycosis should be considered in the differential diagnosis of infiltrative pelvic masses. A conservative diagnostic surgical approach combined with prolonged antibiotic therapy may avoid unnecessary radical surgery.