Case 1 – Disseminated abdominopelvic actinomycosis mimicking infiltrating peritoneal carcinomatosis: a misdiagnosis of advanced ovarian malignancy

Abstract

In cases of abdominopelvic actinomycosis – a rare suppurative and/or pseudotumoral syndrome sometimes simulating a peritoneal carcinomatosis – the misdiagnosis of advanced ovarian cancer is possible. The differential diagnosis of actinomycosis is very difficult and achieved post-operatively in most cases, often after demolitive debulking surgery. We report a case of a 49-year-old woman, an intrauterine device (IUD) user for 8 years, with clinical findings, diagnostic imaging and CA125 levels (238.7 IU/mL) suggesting an advanced ovarian malignancy. The patient underwent surgical exploration showing a widespread bilateral adnexal tumour with disseminated and bowel-infiltrating peritoneal carcinomatosis, after which a complete cytoreduction was performed with a definitive pathological diagnosis of abdominopelvic granulomatous and suppurative infection by Actinomyces israelii, and no evidence of malignancy.