Pelvic actinomycosis is an uncommon chronic infection primarily associated with prolonged intrauterine device (IUD) use in women. It often resembles ovarian malignancies due to overlapping clinical and imaging characteristics, leading to potential misdiagnosis.

This case series aims to highlight the diagnostic challenges and management of pelvic actinomycosis in patients presenting with pelvic masses that mimic ovarian tumors, particularly in cases lacking the conventional IUD-related risk factor.

Three female patients with suspected ovarian tumors, based on clinical symptoms, imaging, and elevated CA-125 levels, were reviewed. Each patient underwent staging laparotomy, followed by histopathological examination of the resected masses. Surgical findings, including the presence of sulfur granules and Splendore-Hoeppli phenomenon, confirmed actinomycotic infection in all cases. Post-surgical treatment included prolonged antibiotic regimens tailored to each case.

Histopathology revealed that all patients had extensive actinomycotic infection, marked by inflammatory and fibrotic changes. Notably, none of the patients had a history of IUD use, which is atypical for pelvic actinomycosis cases. Following surgery and antibiotic treatment, all patients achieved full recovery without recurrence, underscoring the effectiveness of this combined approach.

The cases underscore the need to include pelvic actinomycosis in the differential diagnosis of complex pelvic masses to avoid unnecessary oncologic surgery. Recognizing actinomycosis, even in the absence of typical risk factors, can guide timely antibiotic therapy, with surgery reserved for diagnostic and severe cases. This case series enhances the understanding of pelvic actinomycosis and informs strategies for diagnosis and management.